To find all the divisors of the number 8,720,920:
- 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 8,720,920:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
8,720,920 = 23 × 5 × 13 × 31 × 541
8,720,920 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), ...
How to count the number of factors of a number?
Without actually finding the factors
- If a number N is prime factorized as:
N = am × bk × cz
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 = (3 + 1) × (1 + 1) × (1 + 1) × (1 + 1) × (1 + 1) = 4 × 2 × 2 × 2 × 2 = 64
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 8,720,920
- 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
composite factor = 2
2 =
4
prime factor =
5
composite factor = 2
3 =
8
composite factor = 2 × 5 =
10
prime factor =
13
composite factor = 2
2 × 5 =
20
composite factor = 2 × 13 =
26
prime factor =
31
composite factor = 2
3 × 5 =
40
composite factor = 2
2 × 13 =
52
composite factor = 2 × 31 =
62
composite factor = 5 × 13 =
65
composite factor = 2
3 × 13 =
104
composite factor = 2
2 × 31 =
124
composite factor = 2 × 5 × 13 =
130
composite factor = 5 × 31 =
155
composite factor = 2
3 × 31 =
248
composite factor = 2
2 × 5 × 13 =
260
composite factor = 2 × 5 × 31 =
310
composite factor = 13 × 31 =
403
composite factor = 2
3 × 5 × 13 =
520
prime factor =
541
composite factor = 2
2 × 5 × 31 =
620
composite factor = 2 × 13 × 31 =
806
composite factor = 2 × 541 =
1,082
composite factor = 2
3 × 5 × 31 =
1,240
composite factor = 2
2 × 13 × 31 =
1,612
composite factor = 5 × 13 × 31 =
2,015
composite factor = 2
2 × 541 =
2,164
composite factor = 5 × 541 =
2,705
This list continues below...
... This list continues from above
composite factor = 2
3 × 13 × 31 =
3,224
composite factor = 2 × 5 × 13 × 31 =
4,030
composite factor = 2
3 × 541 =
4,328
composite factor = 2 × 5 × 541 =
5,410
composite factor = 13 × 541 =
7,033
composite factor = 2
2 × 5 × 13 × 31 =
8,060
composite factor = 2
2 × 5 × 541 =
10,820
composite factor = 2 × 13 × 541 =
14,066
composite factor = 2
3 × 5 × 13 × 31 =
16,120
composite factor = 31 × 541 =
16,771
composite factor = 2
3 × 5 × 541 =
21,640
composite factor = 2
2 × 13 × 541 =
28,132
composite factor = 2 × 31 × 541 =
33,542
composite factor = 5 × 13 × 541 =
35,165
composite factor = 2
3 × 13 × 541 =
56,264
composite factor = 2
2 × 31 × 541 =
67,084
composite factor = 2 × 5 × 13 × 541 =
70,330
composite factor = 5 × 31 × 541 =
83,855
composite factor = 2
3 × 31 × 541 =
134,168
composite factor = 2
2 × 5 × 13 × 541 =
140,660
composite factor = 2 × 5 × 31 × 541 =
167,710
composite factor = 13 × 31 × 541 =
218,023
composite factor = 2
3 × 5 × 13 × 541 =
281,320
composite factor = 2
2 × 5 × 31 × 541 =
335,420
composite factor = 2 × 13 × 31 × 541 =
436,046
composite factor = 2
3 × 5 × 31 × 541 =
670,840
composite factor = 2
2 × 13 × 31 × 541 =
872,092
composite factor = 5 × 13 × 31 × 541 =
1,090,115
composite factor = 2
3 × 13 × 31 × 541 =
1,744,184
composite factor = 2 × 5 × 13 × 31 × 541 =
2,180,230
composite factor = 2
2 × 5 × 13 × 31 × 541 =
4,360,460
composite factor = 2
3 × 5 × 13 × 31 × 541 =
8,720,920
64 factors (divisors)
What times what is 8,720,920?
What number multiplied by what number equals 8,720,920?
All the combinations of any two natural numbers whose product equals 8,720,920.
1 × 8,720,920 = 8,720,920
2 × 4,360,460 = 8,720,920
4 × 2,180,230 = 8,720,920
5 × 1,744,184 = 8,720,920
8 × 1,090,115 = 8,720,920
10 × 872,092 = 8,720,920
13 × 670,840 = 8,720,920
20 × 436,046 = 8,720,920
26 × 335,420 = 8,720,920
31 × 281,320 = 8,720,920
40 × 218,023 = 8,720,920
52 × 167,710 = 8,720,920
62 × 140,660 = 8,720,920
65 × 134,168 = 8,720,920
104 × 83,855 = 8,720,920
124 × 70,330 = 8,720,920
130 × 67,084 = 8,720,920
155 × 56,264 = 8,720,920
248 × 35,165 = 8,720,920
260 × 33,542 = 8,720,920
310 × 28,132 = 8,720,920
403 × 21,640 = 8,720,920
520 × 16,771 = 8,720,920
541 × 16,120 = 8,720,920
620 × 14,066 = 8,720,920
806 × 10,820 = 8,720,920
1,082 × 8,060 = 8,720,920
1,240 × 7,033 = 8,720,920
1,612 × 5,410 = 8,720,920
2,015 × 4,328 = 8,720,920
2,164 × 4,030 = 8,720,920
2,705 × 3,224 = 8,720,920
32 unique multiplications The final answer:
(scroll down)