To find all the divisors of the number 8,505:
- 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 8,505:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
8,505 = 35 × 5 × 7
8,505 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 = (5 + 1) × (1 + 1) × (1 + 1) = 6 × 2 × 2 = 24
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 8,505
- 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 =
5
prime factor =
7
composite factor = 3
2 =
9
composite factor = 3 × 5 =
15
composite factor = 3 × 7 =
21
composite factor = 3
3 =
27
composite factor = 5 × 7 =
35
composite factor = 3
2 × 5 =
45
composite factor = 3
2 × 7 =
63
composite factor = 3
4 =
81
This list continues below...
... This list continues from above
composite factor = 3 × 5 × 7 =
105
composite factor = 3
3 × 5 =
135
composite factor = 3
3 × 7 =
189
composite factor = 3
5 =
243
composite factor = 3
2 × 5 × 7 =
315
composite factor = 3
4 × 5 =
405
composite factor = 3
4 × 7 =
567
composite factor = 3
3 × 5 × 7 =
945
composite factor = 3
5 × 5 =
1,215
composite factor = 3
5 × 7 =
1,701
composite factor = 3
4 × 5 × 7 =
2,835
composite factor = 3
5 × 5 × 7 =
8,505
24 factors (divisors)
What times what is 8,505?
What number multiplied by what number equals 8,505?
All the combinations of any two natural numbers whose product equals 8,505.
1 × 8,505 = 8,505
3 × 2,835 = 8,505
5 × 1,701 = 8,505
7 × 1,215 = 8,505
9 × 945 = 8,505
15 × 567 = 8,505
21 × 405 = 8,505
27 × 315 = 8,505
35 × 243 = 8,505
45 × 189 = 8,505
63 × 135 = 8,505
81 × 105 = 8,505
12 unique multiplications The final answer:
(scroll down)