To find all the divisors of the number 120,428:
- 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 120,428:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
120,428 = 22 × 7 × 11 × 17 × 23
120,428 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 = (2 + 1) × (1 + 1) × (1 + 1) × (1 + 1) × (1 + 1) = 3 × 2 × 2 × 2 × 2 = 48
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 120,428
- 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 =
7
prime factor =
11
composite factor = 2 × 7 =
14
prime factor =
17
composite factor = 2 × 11 =
22
prime factor =
23
composite factor = 2
2 × 7 =
28
composite factor = 2 × 17 =
34
composite factor = 2
2 × 11 =
44
composite factor = 2 × 23 =
46
composite factor = 2
2 × 17 =
68
composite factor = 7 × 11 =
77
composite factor = 2
2 × 23 =
92
composite factor = 7 × 17 =
119
composite factor = 2 × 7 × 11 =
154
composite factor = 7 × 23 =
161
composite factor = 11 × 17 =
187
composite factor = 2 × 7 × 17 =
238
composite factor = 11 × 23 =
253
composite factor = 2
2 × 7 × 11 =
308
composite factor = 2 × 7 × 23 =
322
This list continues below...
... This list continues from above
composite factor = 2 × 11 × 17 =
374
composite factor = 17 × 23 =
391
composite factor = 2
2 × 7 × 17 =
476
composite factor = 2 × 11 × 23 =
506
composite factor = 2
2 × 7 × 23 =
644
composite factor = 2
2 × 11 × 17 =
748
composite factor = 2 × 17 × 23 =
782
composite factor = 2
2 × 11 × 23 =
1,012
composite factor = 7 × 11 × 17 =
1,309
composite factor = 2
2 × 17 × 23 =
1,564
composite factor = 7 × 11 × 23 =
1,771
composite factor = 2 × 7 × 11 × 17 =
2,618
composite factor = 7 × 17 × 23 =
2,737
composite factor = 2 × 7 × 11 × 23 =
3,542
composite factor = 11 × 17 × 23 =
4,301
composite factor = 2
2 × 7 × 11 × 17 =
5,236
composite factor = 2 × 7 × 17 × 23 =
5,474
composite factor = 2
2 × 7 × 11 × 23 =
7,084
composite factor = 2 × 11 × 17 × 23 =
8,602
composite factor = 2
2 × 7 × 17 × 23 =
10,948
composite factor = 2
2 × 11 × 17 × 23 =
17,204
composite factor = 7 × 11 × 17 × 23 =
30,107
composite factor = 2 × 7 × 11 × 17 × 23 =
60,214
composite factor = 2
2 × 7 × 11 × 17 × 23 =
120,428
48 factors (divisors)
What times what is 120,428?
What number multiplied by what number equals 120,428?
All the combinations of any two natural numbers whose product equals 120,428.
1 × 120,428 = 120,428
2 × 60,214 = 120,428
4 × 30,107 = 120,428
7 × 17,204 = 120,428
11 × 10,948 = 120,428
14 × 8,602 = 120,428
17 × 7,084 = 120,428
22 × 5,474 = 120,428
23 × 5,236 = 120,428
28 × 4,301 = 120,428
34 × 3,542 = 120,428
44 × 2,737 = 120,428
46 × 2,618 = 120,428
68 × 1,771 = 120,428
77 × 1,564 = 120,428
92 × 1,309 = 120,428
119 × 1,012 = 120,428
154 × 782 = 120,428
161 × 748 = 120,428
187 × 644 = 120,428
238 × 506 = 120,428
253 × 476 = 120,428
308 × 391 = 120,428
322 × 374 = 120,428
24 unique multiplications The final answer:
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