To find all the divisors of the number 21,959,931:
- 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 21,959,931:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
21,959,931 = 3 × 7 × 29 × 107 × 337
21,959,931 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 = (1 + 1) × (1 + 1) × (1 + 1) × (1 + 1) × (1 + 1) = 2 × 2 × 2 × 2 × 2 = 32
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 21,959,931
- Multiply the prime factors involved in the prime factorization of the number in all their unique combinations, that give different results.
- 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 =
7
composite factor = 3 × 7 =
21
prime factor =
29
composite factor = 3 × 29 =
87
prime factor =
107
composite factor = 7 × 29 =
203
composite factor = 3 × 107 =
321
prime factor =
337
composite factor = 3 × 7 × 29 =
609
composite factor = 7 × 107 =
749
composite factor = 3 × 337 =
1,011
composite factor = 3 × 7 × 107 =
2,247
composite factor = 7 × 337 =
2,359
composite factor = 29 × 107 =
3,103
This list continues below...
... This list continues from above
composite factor = 3 × 7 × 337 =
7,077
composite factor = 3 × 29 × 107 =
9,309
composite factor = 29 × 337 =
9,773
composite factor = 7 × 29 × 107 =
21,721
composite factor = 3 × 29 × 337 =
29,319
composite factor = 107 × 337 =
36,059
composite factor = 3 × 7 × 29 × 107 =
65,163
composite factor = 7 × 29 × 337 =
68,411
composite factor = 3 × 107 × 337 =
108,177
composite factor = 3 × 7 × 29 × 337 =
205,233
composite factor = 7 × 107 × 337 =
252,413
composite factor = 3 × 7 × 107 × 337 =
757,239
composite factor = 29 × 107 × 337 =
1,045,711
composite factor = 3 × 29 × 107 × 337 =
3,137,133
composite factor = 7 × 29 × 107 × 337 =
7,319,977
composite factor = 3 × 7 × 29 × 107 × 337 =
21,959,931
32 factors (divisors)
What times what is 21,959,931?
What number multiplied by what number equals 21,959,931?
All the combinations of any two natural numbers whose product equals 21,959,931.
1 × 21,959,931 = 21,959,931
3 × 7,319,977 = 21,959,931
7 × 3,137,133 = 21,959,931
21 × 1,045,711 = 21,959,931
29 × 757,239 = 21,959,931
87 × 252,413 = 21,959,931
107 × 205,233 = 21,959,931
203 × 108,177 = 21,959,931
321 × 68,411 = 21,959,931
337 × 65,163 = 21,959,931
609 × 36,059 = 21,959,931
749 × 29,319 = 21,959,931
1,011 × 21,721 = 21,959,931
2,247 × 9,773 = 21,959,931
2,359 × 9,309 = 21,959,931
3,103 × 7,077 = 21,959,931
16 unique multiplications The final answer:
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