Factors of 856,426,272. Calculator of Proper, Improper, Prime and Compound Divisors, if Any

All the factors (divisors) of the number 856,426,272. Connection with the prime factorization of the number

Calculations:

Calculate all the (common) factors (divisors) of one or two numbers

To find all the divisors of the number 856,426,272:

1. Decompose the number into prime factors.
See how you can find out how many factors (divisors) the number has, without actually calculating them.
2. Multiply the prime factors in all their unique combinations, that yield different results.

1. Carry out the prime factorization of the number 856,426,272:

The prime factorization of a number: finding the prime numbers that multiply together to make that number.

856,426,272 = 2⁵ × 3 × 13 × 17 × 37 × 1,091
856,426,272 is not a prime number but a composite one.

Prime number: a natural number that is divisible (divided evenly) only by 1 and itself. A prime number has exactly two factors: 1 and the number itself.
Examples of prime numbers: 2 (factors 1, 2), 3 (factors 1, 3), 5 (factors 1, 5), 7 (factors 1, 7), 11 (factors 1, 11), 13 (factors 1, 13), ...
Composite number: a natural number that has at least one factor other than 1 and itself. So it is neither a prime number nor 1.
Examples of composite numbers: 4 (it has 3 factors: 1, 2, 4), 6 (it has 4 factors: 1, 2, 3, 6), 8 (it has 4 factors: 1, 2, 4, 8), 9 (it has 3 factors: 1, 3, 9), 10 (it has 4 factors: 1, 2, 5, 10), 12 (it has 6 factors: 1, 2, 3, 4, 6, 12), ...
» Online calculator. Check whether a number is prime or not. The prime factorization of composite numbers (decomposition into prime factors)

How to count the number of factors of a number?

Without actually finding the factors

If a number N is prime factorized as:
N = a^m × b^k × c^z
where a, b, c are the prime factors and m, k, z are their exponents, natural numbers, ....
...
Then the number of factors of the number N can be calculated as:
n = (m + 1) × (k + 1) × (z + 1)
...
In our case, the number of factors is calculated as:
n = (5 + 1) × (1 + 1) × (1 + 1) × (1 + 1) × (1 + 1) × (1 + 1) = 6 × 2 × 2 × 2 × 2 × 2 = 192

But to actually calculate the factors, see below...

2. Multiply the prime factors of the number 856,426,272

Multiply the prime factors involved in the prime factorization of the number in all their unique combinations, that give different results.
Also consider the exponents of these prime factors.
Also add 1 to the list of factors (divisors). All the numbers are divisible by 1.

All the factors (divisors) are listed below - in ascending order

The list of factors (divisors):

Numbers other than 1 that are not prime factors are composite factors (divisors).

neither prime nor composite = 1

prime factor = 2

prime factor = 3

composite factor = 2² = 4

composite factor = 2 × 3 = 6

composite factor = 2³ = 8

composite factor = 2² × 3 = 12

prime factor = 13

composite factor = 2⁴ = 16

prime factor = 17

composite factor = 2³ × 3 = 24

composite factor = 2 × 13 = 26

composite factor = 2⁵ = 32

composite factor = 2 × 17 = 34

prime factor = 37

composite factor = 3 × 13 = 39

composite factor = 2⁴ × 3 = 48

composite factor = 3 × 17 = 51

composite factor = 2² × 13 = 52

composite factor = 2² × 17 = 68

composite factor = 2 × 37 = 74

composite factor = 2 × 3 × 13 = 78

composite factor = 2⁵ × 3 = 96

composite factor = 2 × 3 × 17 = 102

composite factor = 2³ × 13 = 104

composite factor = 3 × 37 = 111

composite factor = 2³ × 17 = 136

composite factor = 2² × 37 = 148

composite factor = 2² × 3 × 13 = 156

composite factor = 2² × 3 × 17 = 204

composite factor = 2⁴ × 13 = 208

composite factor = 13 × 17 = 221

composite factor = 2 × 3 × 37 = 222

composite factor = 2⁴ × 17 = 272

composite factor = 2³ × 37 = 296

composite factor = 2³ × 3 × 13 = 312

composite factor = 2³ × 3 × 17 = 408

composite factor = 2⁵ × 13 = 416

composite factor = 2 × 13 × 17 = 442

composite factor = 2² × 3 × 37 = 444

composite factor = 13 × 37 = 481

composite factor = 2⁵ × 17 = 544

composite factor = 2⁴ × 37 = 592

composite factor = 2⁴ × 3 × 13 = 624

composite factor = 17 × 37 = 629

composite factor = 3 × 13 × 17 = 663

composite factor = 2⁴ × 3 × 17 = 816

composite factor = 2² × 13 × 17 = 884

composite factor = 2³ × 3 × 37 = 888

composite factor = 2 × 13 × 37 = 962

prime factor = 1,091

composite factor = 2⁵ × 37 = 1,184

composite factor = 2⁵ × 3 × 13 = 1,248

composite factor = 2 × 17 × 37 = 1,258

composite factor = 2 × 3 × 13 × 17 = 1,326

composite factor = 3 × 13 × 37 = 1,443

composite factor = 2⁵ × 3 × 17 = 1,632

composite factor = 2³ × 13 × 17 = 1,768

composite factor = 2⁴ × 3 × 37 = 1,776

composite factor = 3 × 17 × 37 = 1,887

composite factor = 2² × 13 × 37 = 1,924

composite factor = 2 × 1,091 = 2,182

composite factor = 2² × 17 × 37 = 2,516

composite factor = 2² × 3 × 13 × 17 = 2,652

composite factor = 2 × 3 × 13 × 37 = 2,886

composite factor = 3 × 1,091 = 3,273

composite factor = 2⁴ × 13 × 17 = 3,536

composite factor = 2⁵ × 3 × 37 = 3,552

composite factor = 2 × 3 × 17 × 37 = 3,774

composite factor = 2³ × 13 × 37 = 3,848

composite factor = 2² × 1,091 = 4,364

composite factor = 2³ × 17 × 37 = 5,032

composite factor = 2³ × 3 × 13 × 17 = 5,304

composite factor = 2² × 3 × 13 × 37 = 5,772

composite factor = 2 × 3 × 1,091 = 6,546

composite factor = 2⁵ × 13 × 17 = 7,072

composite factor = 2² × 3 × 17 × 37 = 7,548

composite factor = 2⁴ × 13 × 37 = 7,696

composite factor = 13 × 17 × 37 = 8,177

composite factor = 2³ × 1,091 = 8,728

composite factor = 2⁴ × 17 × 37 = 10,064

composite factor = 2⁴ × 3 × 13 × 17 = 10,608

composite factor = 2³ × 3 × 13 × 37 = 11,544

composite factor = 2² × 3 × 1,091 = 13,092

composite factor = 13 × 1,091 = 14,183

composite factor = 2³ × 3 × 17 × 37 = 15,096

composite factor = 2⁵ × 13 × 37 = 15,392

composite factor = 2 × 13 × 17 × 37 = 16,354

composite factor = 2⁴ × 1,091 = 17,456

composite factor = 17 × 1,091 = 18,547

composite factor = 2⁵ × 17 × 37 = 20,128

composite factor = 2⁵ × 3 × 13 × 17 = 21,216

composite factor = 2⁴ × 3 × 13 × 37 = 23,088

composite factor = 3 × 13 × 17 × 37 = 24,531

composite factor = 2³ × 3 × 1,091 = 26,184

composite factor = 2 × 13 × 1,091 = 28,366

This list continues below...

... This list continues from above

composite factor = 2⁴ × 3 × 17 × 37 = 30,192

composite factor = 2² × 13 × 17 × 37 = 32,708

composite factor = 2⁵ × 1,091 = 34,912

composite factor = 2 × 17 × 1,091 = 37,094

composite factor = 37 × 1,091 = 40,367

composite factor = 3 × 13 × 1,091 = 42,549

composite factor = 2⁵ × 3 × 13 × 37 = 46,176

composite factor = 2 × 3 × 13 × 17 × 37 = 49,062

composite factor = 2⁴ × 3 × 1,091 = 52,368

composite factor = 3 × 17 × 1,091 = 55,641

composite factor = 2² × 13 × 1,091 = 56,732

composite factor = 2⁵ × 3 × 17 × 37 = 60,384

composite factor = 2³ × 13 × 17 × 37 = 65,416

composite factor = 2² × 17 × 1,091 = 74,188

composite factor = 2 × 37 × 1,091 = 80,734

composite factor = 2 × 3 × 13 × 1,091 = 85,098

composite factor = 2² × 3 × 13 × 17 × 37 = 98,124

composite factor = 2⁵ × 3 × 1,091 = 104,736

composite factor = 2 × 3 × 17 × 1,091 = 111,282

composite factor = 2³ × 13 × 1,091 = 113,464

composite factor = 3 × 37 × 1,091 = 121,101

composite factor = 2⁴ × 13 × 17 × 37 = 130,832

composite factor = 2³ × 17 × 1,091 = 148,376

composite factor = 2² × 37 × 1,091 = 161,468

composite factor = 2² × 3 × 13 × 1,091 = 170,196

composite factor = 2³ × 3 × 13 × 17 × 37 = 196,248

composite factor = 2² × 3 × 17 × 1,091 = 222,564

composite factor = 2⁴ × 13 × 1,091 = 226,928

composite factor = 13 × 17 × 1,091 = 241,111

composite factor = 2 × 3 × 37 × 1,091 = 242,202

composite factor = 2⁵ × 13 × 17 × 37 = 261,664

composite factor = 2⁴ × 17 × 1,091 = 296,752

composite factor = 2³ × 37 × 1,091 = 322,936

composite factor = 2³ × 3 × 13 × 1,091 = 340,392

composite factor = 2⁴ × 3 × 13 × 17 × 37 = 392,496

composite factor = 2³ × 3 × 17 × 1,091 = 445,128

composite factor = 2⁵ × 13 × 1,091 = 453,856

composite factor = 2 × 13 × 17 × 1,091 = 482,222

composite factor = 2² × 3 × 37 × 1,091 = 484,404

composite factor = 13 × 37 × 1,091 = 524,771

composite factor = 2⁵ × 17 × 1,091 = 593,504

composite factor = 2⁴ × 37 × 1,091 = 645,872

composite factor = 2⁴ × 3 × 13 × 1,091 = 680,784

composite factor = 17 × 37 × 1,091 = 686,239

composite factor = 3 × 13 × 17 × 1,091 = 723,333

composite factor = 2⁵ × 3 × 13 × 17 × 37 = 784,992

composite factor = 2⁴ × 3 × 17 × 1,091 = 890,256

composite factor = 2² × 13 × 17 × 1,091 = 964,444

composite factor = 2³ × 3 × 37 × 1,091 = 968,808

composite factor = 2 × 13 × 37 × 1,091 = 1,049,542

composite factor = 2⁵ × 37 × 1,091 = 1,291,744

composite factor = 2⁵ × 3 × 13 × 1,091 = 1,361,568

composite factor = 2 × 17 × 37 × 1,091 = 1,372,478

composite factor = 2 × 3 × 13 × 17 × 1,091 = 1,446,666

composite factor = 3 × 13 × 37 × 1,091 = 1,574,313

composite factor = 2⁵ × 3 × 17 × 1,091 = 1,780,512

composite factor = 2³ × 13 × 17 × 1,091 = 1,928,888

composite factor = 2⁴ × 3 × 37 × 1,091 = 1,937,616

composite factor = 3 × 17 × 37 × 1,091 = 2,058,717

composite factor = 2² × 13 × 37 × 1,091 = 2,099,084

composite factor = 2² × 17 × 37 × 1,091 = 2,744,956

composite factor = 2² × 3 × 13 × 17 × 1,091 = 2,893,332

composite factor = 2 × 3 × 13 × 37 × 1,091 = 3,148,626

composite factor = 2⁴ × 13 × 17 × 1,091 = 3,857,776

composite factor = 2⁵ × 3 × 37 × 1,091 = 3,875,232

composite factor = 2 × 3 × 17 × 37 × 1,091 = 4,117,434

composite factor = 2³ × 13 × 37 × 1,091 = 4,198,168

composite factor = 2³ × 17 × 37 × 1,091 = 5,489,912

composite factor = 2³ × 3 × 13 × 17 × 1,091 = 5,786,664

composite factor = 2² × 3 × 13 × 37 × 1,091 = 6,297,252

composite factor = 2⁵ × 13 × 17 × 1,091 = 7,715,552

composite factor = 2² × 3 × 17 × 37 × 1,091 = 8,234,868

composite factor = 2⁴ × 13 × 37 × 1,091 = 8,396,336

composite factor = 13 × 17 × 37 × 1,091 = 8,921,107

composite factor = 2⁴ × 17 × 37 × 1,091 = 10,979,824

composite factor = 2⁴ × 3 × 13 × 17 × 1,091 = 11,573,328

composite factor = 2³ × 3 × 13 × 37 × 1,091 = 12,594,504

composite factor = 2³ × 3 × 17 × 37 × 1,091 = 16,469,736

composite factor = 2⁵ × 13 × 37 × 1,091 = 16,792,672

composite factor = 2 × 13 × 17 × 37 × 1,091 = 17,842,214

composite factor = 2⁵ × 17 × 37 × 1,091 = 21,959,648

composite factor = 2⁵ × 3 × 13 × 17 × 1,091 = 23,146,656

composite factor = 2⁴ × 3 × 13 × 37 × 1,091 = 25,189,008

composite factor = 3 × 13 × 17 × 37 × 1,091 = 26,763,321

composite factor = 2⁴ × 3 × 17 × 37 × 1,091 = 32,939,472

composite factor = 2² × 13 × 17 × 37 × 1,091 = 35,684,428

composite factor = 2⁵ × 3 × 13 × 37 × 1,091 = 50,378,016

composite factor = 2 × 3 × 13 × 17 × 37 × 1,091 = 53,526,642

composite factor = 2⁵ × 3 × 17 × 37 × 1,091 = 65,878,944

composite factor = 2³ × 13 × 17 × 37 × 1,091 = 71,368,856

composite factor = 2² × 3 × 13 × 17 × 37 × 1,091 = 107,053,284

composite factor = 2⁴ × 13 × 17 × 37 × 1,091 = 142,737,712

composite factor = 2³ × 3 × 13 × 17 × 37 × 1,091 = 214,106,568

composite factor = 2⁵ × 13 × 17 × 37 × 1,091 = 285,475,424

composite factor = 2⁴ × 3 × 13 × 17 × 37 × 1,091 = 428,213,136

composite factor = 2⁵ × 3 × 13 × 17 × 37 × 1,091 = 856,426,272

192 factors (divisors)

What times what is 856,426,272?
What number multiplied by what number equals 856,426,272?

All the combinations of any two natural numbers whose product equals 856,426,272.

1 × 856,426,272 = 856,426,272

2 × 428,213,136 = 856,426,272

3 × 285,475,424 = 856,426,272

4 × 214,106,568 = 856,426,272

6 × 142,737,712 = 856,426,272

8 × 107,053,284 = 856,426,272

12 × 71,368,856 = 856,426,272

13 × 65,878,944 = 856,426,272

16 × 53,526,642 = 856,426,272

17 × 50,378,016 = 856,426,272

24 × 35,684,428 = 856,426,272

26 × 32,939,472 = 856,426,272

32 × 26,763,321 = 856,426,272

34 × 25,189,008 = 856,426,272

37 × 23,146,656 = 856,426,272

39 × 21,959,648 = 856,426,272

48 × 17,842,214 = 856,426,272

51 × 16,792,672 = 856,426,272

52 × 16,469,736 = 856,426,272

68 × 12,594,504 = 856,426,272

74 × 11,573,328 = 856,426,272

78 × 10,979,824 = 856,426,272

96 × 8,921,107 = 856,426,272

102 × 8,396,336 = 856,426,272

104 × 8,234,868 = 856,426,272

111 × 7,715,552 = 856,426,272

136 × 6,297,252 = 856,426,272

148 × 5,786,664 = 856,426,272

156 × 5,489,912 = 856,426,272

204 × 4,198,168 = 856,426,272

208 × 4,117,434 = 856,426,272

221 × 3,875,232 = 856,426,272

222 × 3,857,776 = 856,426,272

272 × 3,148,626 = 856,426,272

296 × 2,893,332 = 856,426,272

312 × 2,744,956 = 856,426,272

408 × 2,099,084 = 856,426,272

416 × 2,058,717 = 856,426,272

442 × 1,937,616 = 856,426,272

444 × 1,928,888 = 856,426,272

481 × 1,780,512 = 856,426,272

544 × 1,574,313 = 856,426,272

592 × 1,446,666 = 856,426,272

624 × 1,372,478 = 856,426,272

629 × 1,361,568 = 856,426,272

663 × 1,291,744 = 856,426,272

816 × 1,049,542 = 856,426,272

884 × 968,808 = 856,426,272

888 × 964,444 = 856,426,272

962 × 890,256 = 856,426,272

1,091 × 784,992 = 856,426,272

1,184 × 723,333 = 856,426,272

1,248 × 686,239 = 856,426,272

1,258 × 680,784 = 856,426,272

1,326 × 645,872 = 856,426,272

1,443 × 593,504 = 856,426,272

1,632 × 524,771 = 856,426,272

1,768 × 484,404 = 856,426,272

1,776 × 482,222 = 856,426,272

1,887 × 453,856 = 856,426,272

1,924 × 445,128 = 856,426,272

2,182 × 392,496 = 856,426,272

2,516 × 340,392 = 856,426,272

2,652 × 322,936 = 856,426,272

2,886 × 296,752 = 856,426,272

3,273 × 261,664 = 856,426,272

3,536 × 242,202 = 856,426,272

3,552 × 241,111 = 856,426,272

3,774 × 226,928 = 856,426,272

3,848 × 222,564 = 856,426,272

4,364 × 196,248 = 856,426,272

5,032 × 170,196 = 856,426,272

5,304 × 161,468 = 856,426,272

5,772 × 148,376 = 856,426,272

6,546 × 130,832 = 856,426,272

7,072 × 121,101 = 856,426,272

7,548 × 113,464 = 856,426,272

7,696 × 111,282 = 856,426,272

8,177 × 104,736 = 856,426,272

8,728 × 98,124 = 856,426,272

10,064 × 85,098 = 856,426,272

10,608 × 80,734 = 856,426,272

11,544 × 74,188 = 856,426,272

13,092 × 65,416 = 856,426,272

14,183 × 60,384 = 856,426,272

15,096 × 56,732 = 856,426,272

15,392 × 55,641 = 856,426,272

16,354 × 52,368 = 856,426,272

17,456 × 49,062 = 856,426,272

18,547 × 46,176 = 856,426,272

20,128 × 42,549 = 856,426,272

21,216 × 40,367 = 856,426,272

23,088 × 37,094 = 856,426,272

24,531 × 34,912 = 856,426,272

26,184 × 32,708 = 856,426,272

28,366 × 30,192 = 856,426,272

96 unique multiplications

The final answer:
(scroll down)

856,426,272 has 192 factors (divisors):
1; 2; 3; 4; 6; 8; 12; 13; 16; 17; 24; 26; 32; 34; 37; 39; 48; 51; 52; 68; 74; 78; 96; 102; 104; 111; 136; 148; 156; 204; 208; 221; 222; 272; 296; 312; 408; 416; 442; 444; 481; 544; 592; 624; 629; 663; 816; 884; 888; 962; 1,091; 1,184; 1,248; 1,258; 1,326; 1,443; 1,632; 1,768; 1,776; 1,887; 1,924; 2,182; 2,516; 2,652; 2,886; 3,273; 3,536; 3,552; 3,774; 3,848; 4,364; 5,032; 5,304; 5,772; 6,546; 7,072; 7,548; 7,696; 8,177; 8,728; 10,064; 10,608; 11,544; 13,092; 14,183; 15,096; 15,392; 16,354; 17,456; 18,547; 20,128; 21,216; 23,088; 24,531; 26,184; 28,366; 30,192; 32,708; 34,912; 37,094; 40,367; 42,549; 46,176; 49,062; 52,368; 55,641; 56,732; 60,384; 65,416; 74,188; 80,734; 85,098; 98,124; 104,736; 111,282; 113,464; 121,101; 130,832; 148,376; 161,468; 170,196; 196,248; 222,564; 226,928; 241,111; 242,202; 261,664; 296,752; 322,936; 340,392; 392,496; 445,128; 453,856; 482,222; 484,404; 524,771; 593,504; 645,872; 680,784; 686,239; 723,333; 784,992; 890,256; 964,444; 968,808; 1,049,542; 1,291,744; 1,361,568; 1,372,478; 1,446,666; 1,574,313; 1,780,512; 1,928,888; 1,937,616; 2,058,717; 2,099,084; 2,744,956; 2,893,332; 3,148,626; 3,857,776; 3,875,232; 4,117,434; 4,198,168; 5,489,912; 5,786,664; 6,297,252; 7,715,552; 8,234,868; 8,396,336; 8,921,107; 10,979,824; 11,573,328; 12,594,504; 16,469,736; 16,792,672; 17,842,214; 21,959,648; 23,146,656; 25,189,008; 26,763,321; 32,939,472; 35,684,428; 50,378,016; 53,526,642; 65,878,944; 71,368,856; 107,053,284; 142,737,712; 214,106,568; 285,475,424; 428,213,136 and 856,426,272
out of which 6 prime factors: 2; 3; 13; 17; 37 and 1,091.
Numbers other than 1 that are not prime factors are composite factors (divisors).
856,426,272 and 1 are sometimes called improper factors, the others are called proper factors (proper divisors).

A quick way to find the factors (the divisors) of a number is to break it down into prime factors.
Then multiply the prime factors and their exponents, if any, in all their different combinations.

Similar operations of calculating common factors (divisors):

» Factors of 856,426,250. Calculator of Proper, Improper, Prime and Compound Divisors, if Any

» Monthly Calculations: (Common) Factors (Divisors) of One or Two Numbers

» Month 05, 2026 [May]: (Common) Factors (Divisors) of One or Two Numbers

» Social skills: Your greatest rival, your most powerful ally. NotebookLM YouTube Video of 7.54 minutes

Factors (divisors), common factors (common divisors), the greatest common factor, GCF (also called the greatest common divisor, GCD, or the highest common factor, HCF)

If the number "t" is a factor (divisor) of the number "a" then in the prime factorization of "t" we will only encounter prime factors that also occur in the prime factorization of "a".
If there are exponents involved, the maximum value of an exponent for any base of a power that is found in the prime factorization of "t" (powers, or multiplicities) is at most equal to the exponent of the same base that is involved in the prime factorization of "a".
Hint: 2³ = 2 × 2 × 2 = 8. 2 is called the base and 3 is the exponent. 2³ is the power and 8 is the value of the power. We sometimes say that the number 2 is raised to the power of 3.

For example, 12 is a factor (divisor) of 120 - the remainder is zero when dividing 120 by 12.
Let's look at the prime factorization of both numbers and notice the bases and the exponents that occur in the prime factorization of both numbers:
12 = 2 × 2 × 3 = 2² × 3
120 = 2 × 2 × 2 × 3 × 5 = 2³ × 3 × 5
120 contains all the prime factors of 12, and all its bases' exponents are higher than those of 12.

If "t" is a common factor (divisor) of "a" and "b", then the prime factorization of "t" contains only the common prime factors involved in the prime factorizations of both "a" and "b".
If there are exponents involved, the maximum value of an exponent for any base of a power that is found in the prime factorization of "t" is at most equal to the minimum of the exponents of the same base that is involved in the prime factorization of both "a" and "b".

For example, 12 is the common factor of 48 and 360.
The remainder is zero when dividing either 48 or 360 by 12.
Here there are the prime factorizations of the three numbers, 12, 48 and 360:
12 = 2² × 3
48 = 2⁴ × 3
360 = 2³ × 3² × 5
Please note that 48 and 360 have more factors (divisors): 2, 3, 4, 6, 8, 12, 24. Among them, 24 is the greatest common factor, GCF (or the greatest common divisor, GCD, or the highest common factor, HCF) of 48 and 360.

The greatest common factor, GCF, of two numbers, "a" and "b", is the product of all the common prime factors involved in the prime factorizations of both "a" and "b", taken by the lowest exponents.
Based on this rule it is calculated the greatest common factor, GCF, (or the greatest common divisor GCD, HCF) of several numbers, as shown in the example below...

GCF, GCD (1,260; 3,024; 5,544) = ?
1,260 = 2² × 3²
3,024 = 2⁴ × 3² × 7
5,544 = 2³ × 3² × 7 × 11
The common prime factors are:
2 - its lowest exponent (multiplicity) is: min.(2; 3; 4) = 2
3 - its lowest exponent (multiplicity) is: min.(2; 2; 2) = 2
GCF, GCD (1,260; 3,024; 5,544) = 2² × 3² = 252

Coprime numbers:
If two numbers "a" and "b" have no other common factors (divisors) than 1, gfc, gcd, hcf (a; b) = 1, then the numbers "a" and "b" are called coprime (or relatively prime).

Factors of the GCF
If "a" and "b" are not coprime, then every common factor (divisor) of "a" and "b" is a also a factor (divisor) of the greatest common factor, GCF (greatest common divisor, GCD, highest common factor, HCF) of "a" and "b".