To find all the divisors of the number 399,080:
- 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 399,080:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
399,080 = 23 × 5 × 11 × 907
399,080 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 399,080
- 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 =
11
composite factor = 2
2 × 5 =
20
composite factor = 2 × 11 =
22
composite factor = 2
3 × 5 =
40
composite factor = 2
2 × 11 =
44
composite factor = 5 × 11 =
55
composite factor = 2
3 × 11 =
88
composite factor = 2 × 5 × 11 =
110
composite factor = 2
2 × 5 × 11 =
220
composite factor = 2
3 × 5 × 11 =
440
This list continues below...
... This list continues from above
prime factor =
907
composite factor = 2 × 907 =
1,814
composite factor = 2
2 × 907 =
3,628
composite factor = 5 × 907 =
4,535
composite factor = 2
3 × 907 =
7,256
composite factor = 2 × 5 × 907 =
9,070
composite factor = 11 × 907 =
9,977
composite factor = 2
2 × 5 × 907 =
18,140
composite factor = 2 × 11 × 907 =
19,954
composite factor = 2
3 × 5 × 907 =
36,280
composite factor = 2
2 × 11 × 907 =
39,908
composite factor = 5 × 11 × 907 =
49,885
composite factor = 2
3 × 11 × 907 =
79,816
composite factor = 2 × 5 × 11 × 907 =
99,770
composite factor = 2
2 × 5 × 11 × 907 =
199,540
composite factor = 2
3 × 5 × 11 × 907 =
399,080
32 factors (divisors)
What times what is 399,080?
What number multiplied by what number equals 399,080?
All the combinations of any two natural numbers whose product equals 399,080.
1 × 399,080 = 399,080
2 × 199,540 = 399,080
4 × 99,770 = 399,080
5 × 79,816 = 399,080
8 × 49,885 = 399,080
10 × 39,908 = 399,080
11 × 36,280 = 399,080
20 × 19,954 = 399,080
22 × 18,140 = 399,080
40 × 9,977 = 399,080
44 × 9,070 = 399,080
55 × 7,256 = 399,080
88 × 4,535 = 399,080
110 × 3,628 = 399,080
220 × 1,814 = 399,080
440 × 907 = 399,080
16 unique multiplications The final answer:
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