To find all the divisors of the number 400,491:
- 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 400,491:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
400,491 = 33 × 7 × 13 × 163
400,491 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) = 4 × 2 × 2 × 2 = 32
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 400,491
- 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 =
7
composite factor = 3
2 =
9
prime factor =
13
composite factor = 3 × 7 =
21
composite factor = 3
3 =
27
composite factor = 3 × 13 =
39
composite factor = 3
2 × 7 =
63
composite factor = 7 × 13 =
91
composite factor = 3
2 × 13 =
117
prime factor =
163
composite factor = 3
3 × 7 =
189
composite factor = 3 × 7 × 13 =
273
composite factor = 3
3 × 13 =
351
composite factor = 3 × 163 =
489
This list continues below...
... This list continues from above
composite factor = 3
2 × 7 × 13 =
819
composite factor = 7 × 163 =
1,141
composite factor = 3
2 × 163 =
1,467
composite factor = 13 × 163 =
2,119
composite factor = 3
3 × 7 × 13 =
2,457
composite factor = 3 × 7 × 163 =
3,423
composite factor = 3
3 × 163 =
4,401
composite factor = 3 × 13 × 163 =
6,357
composite factor = 3
2 × 7 × 163 =
10,269
composite factor = 7 × 13 × 163 =
14,833
composite factor = 3
2 × 13 × 163 =
19,071
composite factor = 3
3 × 7 × 163 =
30,807
composite factor = 3 × 7 × 13 × 163 =
44,499
composite factor = 3
3 × 13 × 163 =
57,213
composite factor = 3
2 × 7 × 13 × 163 =
133,497
composite factor = 3
3 × 7 × 13 × 163 =
400,491
32 factors (divisors)
What times what is 400,491?
What number multiplied by what number equals 400,491?
All the combinations of any two natural numbers whose product equals 400,491.
1 × 400,491 = 400,491
3 × 133,497 = 400,491
7 × 57,213 = 400,491
9 × 44,499 = 400,491
13 × 30,807 = 400,491
21 × 19,071 = 400,491
27 × 14,833 = 400,491
39 × 10,269 = 400,491
63 × 6,357 = 400,491
91 × 4,401 = 400,491
117 × 3,423 = 400,491
163 × 2,457 = 400,491
189 × 2,119 = 400,491
273 × 1,467 = 400,491
351 × 1,141 = 400,491
489 × 819 = 400,491
16 unique multiplications The final answer:
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