To find all the divisors of the number 219,765:
- 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 219,765:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
219,765 = 3 × 5 × 72 × 13 × 23
219,765 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) × (2 + 1) × (1 + 1) × (1 + 1) = 2 × 2 × 3 × 2 × 2 = 48
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 219,765
- 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
prime factor =
13
composite factor = 3 × 5 =
15
composite factor = 3 × 7 =
21
prime factor =
23
composite factor = 5 × 7 =
35
composite factor = 3 × 13 =
39
composite factor = 7
2 =
49
composite factor = 5 × 13 =
65
composite factor = 3 × 23 =
69
composite factor = 7 × 13 =
91
composite factor = 3 × 5 × 7 =
105
composite factor = 5 × 23 =
115
composite factor = 3 × 7
2 =
147
composite factor = 7 × 23 =
161
composite factor = 3 × 5 × 13 =
195
composite factor = 5 × 7
2 =
245
composite factor = 3 × 7 × 13 =
273
composite factor = 13 × 23 =
299
composite factor = 3 × 5 × 23 =
345
composite factor = 5 × 7 × 13 =
455
This list continues below...
... This list continues from above
composite factor = 3 × 7 × 23 =
483
composite factor = 7
2 × 13 =
637
composite factor = 3 × 5 × 7
2 =
735
composite factor = 5 × 7 × 23 =
805
composite factor = 3 × 13 × 23 =
897
composite factor = 7
2 × 23 =
1,127
composite factor = 3 × 5 × 7 × 13 =
1,365
composite factor = 5 × 13 × 23 =
1,495
composite factor = 3 × 7
2 × 13 =
1,911
composite factor = 7 × 13 × 23 =
2,093
composite factor = 3 × 5 × 7 × 23 =
2,415
composite factor = 5 × 7
2 × 13 =
3,185
composite factor = 3 × 7
2 × 23 =
3,381
composite factor = 3 × 5 × 13 × 23 =
4,485
composite factor = 5 × 7
2 × 23 =
5,635
composite factor = 3 × 7 × 13 × 23 =
6,279
composite factor = 3 × 5 × 7
2 × 13 =
9,555
composite factor = 5 × 7 × 13 × 23 =
10,465
composite factor = 7
2 × 13 × 23 =
14,651
composite factor = 3 × 5 × 7
2 × 23 =
16,905
composite factor = 3 × 5 × 7 × 13 × 23 =
31,395
composite factor = 3 × 7
2 × 13 × 23 =
43,953
composite factor = 5 × 7
2 × 13 × 23 =
73,255
composite factor = 3 × 5 × 7
2 × 13 × 23 =
219,765
48 factors (divisors)
What times what is 219,765?
What number multiplied by what number equals 219,765?
All the combinations of any two natural numbers whose product equals 219,765.
1 × 219,765 = 219,765
3 × 73,255 = 219,765
5 × 43,953 = 219,765
7 × 31,395 = 219,765
13 × 16,905 = 219,765
15 × 14,651 = 219,765
21 × 10,465 = 219,765
23 × 9,555 = 219,765
35 × 6,279 = 219,765
39 × 5,635 = 219,765
49 × 4,485 = 219,765
65 × 3,381 = 219,765
69 × 3,185 = 219,765
91 × 2,415 = 219,765
105 × 2,093 = 219,765
115 × 1,911 = 219,765
147 × 1,495 = 219,765
161 × 1,365 = 219,765
195 × 1,127 = 219,765
245 × 897 = 219,765
273 × 805 = 219,765
299 × 735 = 219,765
345 × 637 = 219,765
455 × 483 = 219,765
24 unique multiplications The final answer:
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