To find all the divisors of the number 21,959,472:
- 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 21,959,472:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
21,959,472 = 24 × 3 × 79 × 5,791
21,959,472 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 = (4 + 1) × (1 + 1) × (1 + 1) × (1 + 1) = 5 × 2 × 2 × 2 = 40
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 21,959,472
- 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 = 2
2 =
4
composite factor = 2 × 3 =
6
composite factor = 2
3 =
8
composite factor = 2
2 × 3 =
12
composite factor = 2
4 =
16
composite factor = 2
3 × 3 =
24
composite factor = 2
4 × 3 =
48
prime factor =
79
composite factor = 2 × 79 =
158
composite factor = 3 × 79 =
237
composite factor = 2
2 × 79 =
316
composite factor = 2 × 3 × 79 =
474
composite factor = 2
3 × 79 =
632
composite factor = 2
2 × 3 × 79 =
948
composite factor = 2
4 × 79 =
1,264
composite factor = 2
3 × 3 × 79 =
1,896
composite factor = 2
4 × 3 × 79 =
3,792
This list continues below...
... This list continues from above
prime factor =
5,791
composite factor = 2 × 5,791 =
11,582
composite factor = 3 × 5,791 =
17,373
composite factor = 2
2 × 5,791 =
23,164
composite factor = 2 × 3 × 5,791 =
34,746
composite factor = 2
3 × 5,791 =
46,328
composite factor = 2
2 × 3 × 5,791 =
69,492
composite factor = 2
4 × 5,791 =
92,656
composite factor = 2
3 × 3 × 5,791 =
138,984
composite factor = 2
4 × 3 × 5,791 =
277,968
composite factor = 79 × 5,791 =
457,489
composite factor = 2 × 79 × 5,791 =
914,978
composite factor = 3 × 79 × 5,791 =
1,372,467
composite factor = 2
2 × 79 × 5,791 =
1,829,956
composite factor = 2 × 3 × 79 × 5,791 =
2,744,934
composite factor = 2
3 × 79 × 5,791 =
3,659,912
composite factor = 2
2 × 3 × 79 × 5,791 =
5,489,868
composite factor = 2
4 × 79 × 5,791 =
7,319,824
composite factor = 2
3 × 3 × 79 × 5,791 =
10,979,736
composite factor = 2
4 × 3 × 79 × 5,791 =
21,959,472
40 factors (divisors)
What times what is 21,959,472?
What number multiplied by what number equals 21,959,472?
All the combinations of any two natural numbers whose product equals 21,959,472.
1 × 21,959,472 = 21,959,472
2 × 10,979,736 = 21,959,472
3 × 7,319,824 = 21,959,472
4 × 5,489,868 = 21,959,472
6 × 3,659,912 = 21,959,472
8 × 2,744,934 = 21,959,472
12 × 1,829,956 = 21,959,472
16 × 1,372,467 = 21,959,472
24 × 914,978 = 21,959,472
48 × 457,489 = 21,959,472
79 × 277,968 = 21,959,472
158 × 138,984 = 21,959,472
237 × 92,656 = 21,959,472
316 × 69,492 = 21,959,472
474 × 46,328 = 21,959,472
632 × 34,746 = 21,959,472
948 × 23,164 = 21,959,472
1,264 × 17,373 = 21,959,472
1,896 × 11,582 = 21,959,472
3,792 × 5,791 = 21,959,472
20 unique multiplications The final answer:
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