To find all the divisors of the number 18,480:
- 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 18,480:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
18,480 = 24 × 3 × 5 × 7 × 11
18,480 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 = (4 + 1) × (1 + 1) × (1 + 1) × (1 + 1) × (1 + 1) = 5 × 2 × 2 × 2 × 2 = 80
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 18,480
- 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
prime factor =
7
composite factor = 2
3 =
8
composite factor = 2 × 5 =
10
prime factor =
11
composite factor = 2
2 × 3 =
12
composite factor = 2 × 7 =
14
composite factor = 3 × 5 =
15
composite factor = 2
4 =
16
composite factor = 2
2 × 5 =
20
composite factor = 3 × 7 =
21
composite factor = 2 × 11 =
22
composite factor = 2
3 × 3 =
24
composite factor = 2
2 × 7 =
28
composite factor = 2 × 3 × 5 =
30
composite factor = 3 × 11 =
33
composite factor = 5 × 7 =
35
composite factor = 2
3 × 5 =
40
composite factor = 2 × 3 × 7 =
42
composite factor = 2
2 × 11 =
44
composite factor = 2
4 × 3 =
48
composite factor = 5 × 11 =
55
composite factor = 2
3 × 7 =
56
composite factor = 2
2 × 3 × 5 =
60
composite factor = 2 × 3 × 11 =
66
composite factor = 2 × 5 × 7 =
70
composite factor = 7 × 11 =
77
composite factor = 2
4 × 5 =
80
composite factor = 2
2 × 3 × 7 =
84
composite factor = 2
3 × 11 =
88
composite factor = 3 × 5 × 7 =
105
composite factor = 2 × 5 × 11 =
110
composite factor = 2
4 × 7 =
112
composite factor = 2
3 × 3 × 5 =
120
composite factor = 2
2 × 3 × 11 =
132
This list continues below...
... This list continues from above
composite factor = 2
2 × 5 × 7 =
140
composite factor = 2 × 7 × 11 =
154
composite factor = 3 × 5 × 11 =
165
composite factor = 2
3 × 3 × 7 =
168
composite factor = 2
4 × 11 =
176
composite factor = 2 × 3 × 5 × 7 =
210
composite factor = 2
2 × 5 × 11 =
220
composite factor = 3 × 7 × 11 =
231
composite factor = 2
4 × 3 × 5 =
240
composite factor = 2
3 × 3 × 11 =
264
composite factor = 2
3 × 5 × 7 =
280
composite factor = 2
2 × 7 × 11 =
308
composite factor = 2 × 3 × 5 × 11 =
330
composite factor = 2
4 × 3 × 7 =
336
composite factor = 5 × 7 × 11 =
385
composite factor = 2
2 × 3 × 5 × 7 =
420
composite factor = 2
3 × 5 × 11 =
440
composite factor = 2 × 3 × 7 × 11 =
462
composite factor = 2
4 × 3 × 11 =
528
composite factor = 2
4 × 5 × 7 =
560
composite factor = 2
3 × 7 × 11 =
616
composite factor = 2
2 × 3 × 5 × 11 =
660
composite factor = 2 × 5 × 7 × 11 =
770
composite factor = 2
3 × 3 × 5 × 7 =
840
composite factor = 2
4 × 5 × 11 =
880
composite factor = 2
2 × 3 × 7 × 11 =
924
composite factor = 3 × 5 × 7 × 11 =
1,155
composite factor = 2
4 × 7 × 11 =
1,232
composite factor = 2
3 × 3 × 5 × 11 =
1,320
composite factor = 2
2 × 5 × 7 × 11 =
1,540
composite factor = 2
4 × 3 × 5 × 7 =
1,680
composite factor = 2
3 × 3 × 7 × 11 =
1,848
composite factor = 2 × 3 × 5 × 7 × 11 =
2,310
composite factor = 2
4 × 3 × 5 × 11 =
2,640
composite factor = 2
3 × 5 × 7 × 11 =
3,080
composite factor = 2
4 × 3 × 7 × 11 =
3,696
composite factor = 2
2 × 3 × 5 × 7 × 11 =
4,620
composite factor = 2
4 × 5 × 7 × 11 =
6,160
composite factor = 2
3 × 3 × 5 × 7 × 11 =
9,240
composite factor = 2
4 × 3 × 5 × 7 × 11 =
18,480
80 factors (divisors)
What times what is 18,480?
What number multiplied by what number equals 18,480?
All the combinations of any two natural numbers whose product equals 18,480.
1 × 18,480 = 18,480
2 × 9,240 = 18,480
3 × 6,160 = 18,480
4 × 4,620 = 18,480
5 × 3,696 = 18,480
6 × 3,080 = 18,480
7 × 2,640 = 18,480
8 × 2,310 = 18,480
10 × 1,848 = 18,480
11 × 1,680 = 18,480
12 × 1,540 = 18,480
14 × 1,320 = 18,480
15 × 1,232 = 18,480
16 × 1,155 = 18,480
20 × 924 = 18,480
21 × 880 = 18,480
22 × 840 = 18,480
24 × 770 = 18,480
28 × 660 = 18,480
30 × 616 = 18,480
33 × 560 = 18,480
35 × 528 = 18,480
40 × 462 = 18,480
42 × 440 = 18,480
44 × 420 = 18,480
48 × 385 = 18,480
55 × 336 = 18,480
56 × 330 = 18,480
60 × 308 = 18,480
66 × 280 = 18,480
70 × 264 = 18,480
77 × 240 = 18,480
80 × 231 = 18,480
84 × 220 = 18,480
88 × 210 = 18,480
105 × 176 = 18,480
110 × 168 = 18,480
112 × 165 = 18,480
120 × 154 = 18,480
132 × 140 = 18,480
40 unique multiplications The final answer:
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