To find all the divisors of the number 16,320:
- 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 16,320:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
16,320 = 26 × 3 × 5 × 17
16,320 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 = (6 + 1) × (1 + 1) × (1 + 1) × (1 + 1) = 7 × 2 × 2 × 2 = 56
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 16,320
- 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
prime factor =
17
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 × 17 =
34
composite factor = 2
3 × 5 =
40
composite factor = 2
4 × 3 =
48
composite factor = 3 × 17 =
51
composite factor = 2
2 × 3 × 5 =
60
composite factor = 2
6 =
64
composite factor = 2
2 × 17 =
68
composite factor = 2
4 × 5 =
80
composite factor = 5 × 17 =
85
composite factor = 2
5 × 3 =
96
composite factor = 2 × 3 × 17 =
102
composite factor = 2
3 × 3 × 5 =
120
This list continues below...
... This list continues from above
composite factor = 2
3 × 17 =
136
composite factor = 2
5 × 5 =
160
composite factor = 2 × 5 × 17 =
170
composite factor = 2
6 × 3 =
192
composite factor = 2
2 × 3 × 17 =
204
composite factor = 2
4 × 3 × 5 =
240
composite factor = 3 × 5 × 17 =
255
composite factor = 2
4 × 17 =
272
composite factor = 2
6 × 5 =
320
composite factor = 2
2 × 5 × 17 =
340
composite factor = 2
3 × 3 × 17 =
408
composite factor = 2
5 × 3 × 5 =
480
composite factor = 2 × 3 × 5 × 17 =
510
composite factor = 2
5 × 17 =
544
composite factor = 2
3 × 5 × 17 =
680
composite factor = 2
4 × 3 × 17 =
816
composite factor = 2
6 × 3 × 5 =
960
composite factor = 2
2 × 3 × 5 × 17 =
1,020
composite factor = 2
6 × 17 =
1,088
composite factor = 2
4 × 5 × 17 =
1,360
composite factor = 2
5 × 3 × 17 =
1,632
composite factor = 2
3 × 3 × 5 × 17 =
2,040
composite factor = 2
5 × 5 × 17 =
2,720
composite factor = 2
6 × 3 × 17 =
3,264
composite factor = 2
4 × 3 × 5 × 17 =
4,080
composite factor = 2
6 × 5 × 17 =
5,440
composite factor = 2
5 × 3 × 5 × 17 =
8,160
composite factor = 2
6 × 3 × 5 × 17 =
16,320
56 factors (divisors)
What times what is 16,320?
What number multiplied by what number equals 16,320?
All the combinations of any two natural numbers whose product equals 16,320.
1 × 16,320 = 16,320
2 × 8,160 = 16,320
3 × 5,440 = 16,320
4 × 4,080 = 16,320
5 × 3,264 = 16,320
6 × 2,720 = 16,320
8 × 2,040 = 16,320
10 × 1,632 = 16,320
12 × 1,360 = 16,320
15 × 1,088 = 16,320
16 × 1,020 = 16,320
17 × 960 = 16,320
20 × 816 = 16,320
24 × 680 = 16,320
30 × 544 = 16,320
32 × 510 = 16,320
34 × 480 = 16,320
40 × 408 = 16,320
48 × 340 = 16,320
51 × 320 = 16,320
60 × 272 = 16,320
64 × 255 = 16,320
68 × 240 = 16,320
80 × 204 = 16,320
85 × 192 = 16,320
96 × 170 = 16,320
102 × 160 = 16,320
120 × 136 = 16,320
28 unique multiplications The final answer:
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