To find all the divisors of the number 159,705:
- 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 159,705:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
159,705 = 33 × 5 × 7 × 132
159,705 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) × (2 + 1) = 4 × 2 × 2 × 3 = 48
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 159,705
- 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
prime factor =
13
composite factor = 3 × 5 =
15
composite factor = 3 × 7 =
21
composite factor = 3
3 =
27
composite factor = 5 × 7 =
35
composite factor = 3 × 13 =
39
composite factor = 3
2 × 5 =
45
composite factor = 3
2 × 7 =
63
composite factor = 5 × 13 =
65
composite factor = 7 × 13 =
91
composite factor = 3 × 5 × 7 =
105
composite factor = 3
2 × 13 =
117
composite factor = 3
3 × 5 =
135
composite factor = 13
2 =
169
composite factor = 3
3 × 7 =
189
composite factor = 3 × 5 × 13 =
195
composite factor = 3 × 7 × 13 =
273
composite factor = 3
2 × 5 × 7 =
315
composite factor = 3
3 × 13 =
351
This list continues below...
... This list continues from above
composite factor = 5 × 7 × 13 =
455
composite factor = 3 × 13
2 =
507
composite factor = 3
2 × 5 × 13 =
585
composite factor = 3
2 × 7 × 13 =
819
composite factor = 5 × 13
2 =
845
composite factor = 3
3 × 5 × 7 =
945
composite factor = 7 × 13
2 =
1,183
composite factor = 3 × 5 × 7 × 13 =
1,365
composite factor = 3
2 × 13
2 =
1,521
composite factor = 3
3 × 5 × 13 =
1,755
composite factor = 3
3 × 7 × 13 =
2,457
composite factor = 3 × 5 × 13
2 =
2,535
composite factor = 3 × 7 × 13
2 =
3,549
composite factor = 3
2 × 5 × 7 × 13 =
4,095
composite factor = 3
3 × 13
2 =
4,563
composite factor = 5 × 7 × 13
2 =
5,915
composite factor = 3
2 × 5 × 13
2 =
7,605
composite factor = 3
2 × 7 × 13
2 =
10,647
composite factor = 3
3 × 5 × 7 × 13 =
12,285
composite factor = 3 × 5 × 7 × 13
2 =
17,745
composite factor = 3
3 × 5 × 13
2 =
22,815
composite factor = 3
3 × 7 × 13
2 =
31,941
composite factor = 3
2 × 5 × 7 × 13
2 =
53,235
composite factor = 3
3 × 5 × 7 × 13
2 =
159,705
48 factors (divisors)
What times what is 159,705?
What number multiplied by what number equals 159,705?
All the combinations of any two natural numbers whose product equals 159,705.
1 × 159,705 = 159,705
3 × 53,235 = 159,705
5 × 31,941 = 159,705
7 × 22,815 = 159,705
9 × 17,745 = 159,705
13 × 12,285 = 159,705
15 × 10,647 = 159,705
21 × 7,605 = 159,705
27 × 5,915 = 159,705
35 × 4,563 = 159,705
39 × 4,095 = 159,705
45 × 3,549 = 159,705
63 × 2,535 = 159,705
65 × 2,457 = 159,705
91 × 1,755 = 159,705
105 × 1,521 = 159,705
117 × 1,365 = 159,705
135 × 1,183 = 159,705
169 × 945 = 159,705
189 × 845 = 159,705
195 × 819 = 159,705
273 × 585 = 159,705
315 × 507 = 159,705
351 × 455 = 159,705
24 unique multiplications The final answer:
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