To find all the divisors of the number 72,765:
- 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 72,765:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
72,765 = 33 × 5 × 72 × 11
72,765 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) × (2 + 1) × (1 + 1) = 4 × 2 × 3 × 2 = 48
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 72,765
- 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 =
3
prime factor =
5
prime factor =
7
composite factor = 3
2 =
9
prime factor =
11
composite factor = 3 × 5 =
15
composite factor = 3 × 7 =
21
composite factor = 3
3 =
27
composite factor = 3 × 11 =
33
composite factor = 5 × 7 =
35
composite factor = 3
2 × 5 =
45
composite factor = 7
2 =
49
composite factor = 5 × 11 =
55
composite factor = 3
2 × 7 =
63
composite factor = 7 × 11 =
77
composite factor = 3
2 × 11 =
99
composite factor = 3 × 5 × 7 =
105
composite factor = 3
3 × 5 =
135
composite factor = 3 × 7
2 =
147
composite factor = 3 × 5 × 11 =
165
composite factor = 3
3 × 7 =
189
composite factor = 3 × 7 × 11 =
231
composite factor = 5 × 7
2 =
245
This list continues below...
... This list continues from above
composite factor = 3
3 × 11 =
297
composite factor = 3
2 × 5 × 7 =
315
composite factor = 5 × 7 × 11 =
385
composite factor = 3
2 × 7
2 =
441
composite factor = 3
2 × 5 × 11 =
495
composite factor = 7
2 × 11 =
539
composite factor = 3
2 × 7 × 11 =
693
composite factor = 3 × 5 × 7
2 =
735
composite factor = 3
3 × 5 × 7 =
945
composite factor = 3 × 5 × 7 × 11 =
1,155
composite factor = 3
3 × 7
2 =
1,323
composite factor = 3
3 × 5 × 11 =
1,485
composite factor = 3 × 7
2 × 11 =
1,617
composite factor = 3
3 × 7 × 11 =
2,079
composite factor = 3
2 × 5 × 7
2 =
2,205
composite factor = 5 × 7
2 × 11 =
2,695
composite factor = 3
2 × 5 × 7 × 11 =
3,465
composite factor = 3
2 × 7
2 × 11 =
4,851
composite factor = 3
3 × 5 × 7
2 =
6,615
composite factor = 3 × 5 × 7
2 × 11 =
8,085
composite factor = 3
3 × 5 × 7 × 11 =
10,395
composite factor = 3
3 × 7
2 × 11 =
14,553
composite factor = 3
2 × 5 × 7
2 × 11 =
24,255
composite factor = 3
3 × 5 × 7
2 × 11 =
72,765
48 factors (divisors)
What times what is 72,765?
What number multiplied by what number equals 72,765?
All the combinations of any two natural numbers whose product equals 72,765.
1 × 72,765 = 72,765
3 × 24,255 = 72,765
5 × 14,553 = 72,765
7 × 10,395 = 72,765
9 × 8,085 = 72,765
11 × 6,615 = 72,765
15 × 4,851 = 72,765
21 × 3,465 = 72,765
27 × 2,695 = 72,765
33 × 2,205 = 72,765
35 × 2,079 = 72,765
45 × 1,617 = 72,765
49 × 1,485 = 72,765
55 × 1,323 = 72,765
63 × 1,155 = 72,765
77 × 945 = 72,765
99 × 735 = 72,765
105 × 693 = 72,765
135 × 539 = 72,765
147 × 495 = 72,765
165 × 441 = 72,765
189 × 385 = 72,765
231 × 315 = 72,765
245 × 297 = 72,765
24 unique multiplications The final answer:
(scroll down)