To find all the divisors of the number 678,615:
- 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 678,615:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
678,615 = 3 × 5 × 7 × 23 × 281
678,615 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 678,615
- 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 =
5
prime factor =
7
composite factor = 3 × 5 =
15
composite factor = 3 × 7 =
21
prime factor =
23
composite factor = 5 × 7 =
35
composite factor = 3 × 23 =
69
composite factor = 3 × 5 × 7 =
105
composite factor = 5 × 23 =
115
composite factor = 7 × 23 =
161
prime factor =
281
composite factor = 3 × 5 × 23 =
345
composite factor = 3 × 7 × 23 =
483
composite factor = 5 × 7 × 23 =
805
This list continues below...
... This list continues from above
composite factor = 3 × 281 =
843
composite factor = 5 × 281 =
1,405
composite factor = 7 × 281 =
1,967
composite factor = 3 × 5 × 7 × 23 =
2,415
composite factor = 3 × 5 × 281 =
4,215
composite factor = 3 × 7 × 281 =
5,901
composite factor = 23 × 281 =
6,463
composite factor = 5 × 7 × 281 =
9,835
composite factor = 3 × 23 × 281 =
19,389
composite factor = 3 × 5 × 7 × 281 =
29,505
composite factor = 5 × 23 × 281 =
32,315
composite factor = 7 × 23 × 281 =
45,241
composite factor = 3 × 5 × 23 × 281 =
96,945
composite factor = 3 × 7 × 23 × 281 =
135,723
composite factor = 5 × 7 × 23 × 281 =
226,205
composite factor = 3 × 5 × 7 × 23 × 281 =
678,615
32 factors (divisors)
What times what is 678,615?
What number multiplied by what number equals 678,615?
All the combinations of any two natural numbers whose product equals 678,615.
1 × 678,615 = 678,615
3 × 226,205 = 678,615
5 × 135,723 = 678,615
7 × 96,945 = 678,615
15 × 45,241 = 678,615
21 × 32,315 = 678,615
23 × 29,505 = 678,615
35 × 19,389 = 678,615
69 × 9,835 = 678,615
105 × 6,463 = 678,615
115 × 5,901 = 678,615
161 × 4,215 = 678,615
281 × 2,415 = 678,615
345 × 1,967 = 678,615
483 × 1,405 = 678,615
805 × 843 = 678,615
16 unique multiplications The final answer:
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