To find all the divisors of the number 37,920:
- 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 37,920:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
37,920 = 25 × 3 × 5 × 79
37,920 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) × (1 + 1) = 6 × 2 × 2 × 2 = 48
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 37,920
- 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
prime factor =
3
composite factor = 2
2 =
4
prime factor =
5
composite factor = 2 × 3 =
6
composite factor = 2
3 =
8
composite factor = 2 × 5 =
10
composite factor = 2
2 × 3 =
12
composite factor = 3 × 5 =
15
composite factor = 2
4 =
16
composite factor = 2
2 × 5 =
20
composite factor = 2
3 × 3 =
24
composite factor = 2 × 3 × 5 =
30
composite factor = 2
5 =
32
composite factor = 2
3 × 5 =
40
composite factor = 2
4 × 3 =
48
composite factor = 2
2 × 3 × 5 =
60
prime factor =
79
composite factor = 2
4 × 5 =
80
composite factor = 2
5 × 3 =
96
composite factor = 2
3 × 3 × 5 =
120
composite factor = 2 × 79 =
158
composite factor = 2
5 × 5 =
160
This list continues below...
... This list continues from above
composite factor = 3 × 79 =
237
composite factor = 2
4 × 3 × 5 =
240
composite factor = 2
2 × 79 =
316
composite factor = 5 × 79 =
395
composite factor = 2 × 3 × 79 =
474
composite factor = 2
5 × 3 × 5 =
480
composite factor = 2
3 × 79 =
632
composite factor = 2 × 5 × 79 =
790
composite factor = 2
2 × 3 × 79 =
948
composite factor = 3 × 5 × 79 =
1,185
composite factor = 2
4 × 79 =
1,264
composite factor = 2
2 × 5 × 79 =
1,580
composite factor = 2
3 × 3 × 79 =
1,896
composite factor = 2 × 3 × 5 × 79 =
2,370
composite factor = 2
5 × 79 =
2,528
composite factor = 2
3 × 5 × 79 =
3,160
composite factor = 2
4 × 3 × 79 =
3,792
composite factor = 2
2 × 3 × 5 × 79 =
4,740
composite factor = 2
4 × 5 × 79 =
6,320
composite factor = 2
5 × 3 × 79 =
7,584
composite factor = 2
3 × 3 × 5 × 79 =
9,480
composite factor = 2
5 × 5 × 79 =
12,640
composite factor = 2
4 × 3 × 5 × 79 =
18,960
composite factor = 2
5 × 3 × 5 × 79 =
37,920
48 factors (divisors)
What times what is 37,920?
What number multiplied by what number equals 37,920?
All the combinations of any two natural numbers whose product equals 37,920.
1 × 37,920 = 37,920
2 × 18,960 = 37,920
3 × 12,640 = 37,920
4 × 9,480 = 37,920
5 × 7,584 = 37,920
6 × 6,320 = 37,920
8 × 4,740 = 37,920
10 × 3,792 = 37,920
12 × 3,160 = 37,920
15 × 2,528 = 37,920
16 × 2,370 = 37,920
20 × 1,896 = 37,920
24 × 1,580 = 37,920
30 × 1,264 = 37,920
32 × 1,185 = 37,920
40 × 948 = 37,920
48 × 790 = 37,920
60 × 632 = 37,920
79 × 480 = 37,920
80 × 474 = 37,920
96 × 395 = 37,920
120 × 316 = 37,920
158 × 240 = 37,920
160 × 237 = 37,920
24 unique multiplications The final answer:
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