To find all the divisors of the number 87,120:
- 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 87,120:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
87,120 = 24 × 32 × 5 × 112
87,120 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) × (2 + 1) × (1 + 1) × (2 + 1) = 5 × 3 × 2 × 3 = 90
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 87,120
- 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 = 3
2 =
9
composite factor = 2 × 5 =
10
prime factor =
11
composite factor = 2
2 × 3 =
12
composite factor = 3 × 5 =
15
composite factor = 2
4 =
16
composite factor = 2 × 3
2 =
18
composite factor = 2
2 × 5 =
20
composite factor = 2 × 11 =
22
composite factor = 2
3 × 3 =
24
composite factor = 2 × 3 × 5 =
30
composite factor = 3 × 11 =
33
composite factor = 2
2 × 3
2 =
36
composite factor = 2
3 × 5 =
40
composite factor = 2
2 × 11 =
44
composite factor = 3
2 × 5 =
45
composite factor = 2
4 × 3 =
48
composite factor = 5 × 11 =
55
composite factor = 2
2 × 3 × 5 =
60
composite factor = 2 × 3 × 11 =
66
composite factor = 2
3 × 3
2 =
72
composite factor = 2
4 × 5 =
80
composite factor = 2
3 × 11 =
88
composite factor = 2 × 3
2 × 5 =
90
composite factor = 3
2 × 11 =
99
composite factor = 2 × 5 × 11 =
110
composite factor = 2
3 × 3 × 5 =
120
composite factor = 11
2 =
121
composite factor = 2
2 × 3 × 11 =
132
composite factor = 2
4 × 3
2 =
144
composite factor = 3 × 5 × 11 =
165
composite factor = 2
4 × 11 =
176
composite factor = 2
2 × 3
2 × 5 =
180
composite factor = 2 × 3
2 × 11 =
198
composite factor = 2
2 × 5 × 11 =
220
composite factor = 2
4 × 3 × 5 =
240
composite factor = 2 × 11
2 =
242
composite factor = 2
3 × 3 × 11 =
264
This list continues below...
... This list continues from above
composite factor = 2 × 3 × 5 × 11 =
330
composite factor = 2
3 × 3
2 × 5 =
360
composite factor = 3 × 11
2 =
363
composite factor = 2
2 × 3
2 × 11 =
396
composite factor = 2
3 × 5 × 11 =
440
composite factor = 2
2 × 11
2 =
484
composite factor = 3
2 × 5 × 11 =
495
composite factor = 2
4 × 3 × 11 =
528
composite factor = 5 × 11
2 =
605
composite factor = 2
2 × 3 × 5 × 11 =
660
composite factor = 2
4 × 3
2 × 5 =
720
composite factor = 2 × 3 × 11
2 =
726
composite factor = 2
3 × 3
2 × 11 =
792
composite factor = 2
4 × 5 × 11 =
880
composite factor = 2
3 × 11
2 =
968
composite factor = 2 × 3
2 × 5 × 11 =
990
composite factor = 3
2 × 11
2 =
1,089
composite factor = 2 × 5 × 11
2 =
1,210
composite factor = 2
3 × 3 × 5 × 11 =
1,320
composite factor = 2
2 × 3 × 11
2 =
1,452
composite factor = 2
4 × 3
2 × 11 =
1,584
composite factor = 3 × 5 × 11
2 =
1,815
composite factor = 2
4 × 11
2 =
1,936
composite factor = 2
2 × 3
2 × 5 × 11 =
1,980
composite factor = 2 × 3
2 × 11
2 =
2,178
composite factor = 2
2 × 5 × 11
2 =
2,420
composite factor = 2
4 × 3 × 5 × 11 =
2,640
composite factor = 2
3 × 3 × 11
2 =
2,904
composite factor = 2 × 3 × 5 × 11
2 =
3,630
composite factor = 2
3 × 3
2 × 5 × 11 =
3,960
composite factor = 2
2 × 3
2 × 11
2 =
4,356
composite factor = 2
3 × 5 × 11
2 =
4,840
composite factor = 3
2 × 5 × 11
2 =
5,445
composite factor = 2
4 × 3 × 11
2 =
5,808
composite factor = 2
2 × 3 × 5 × 11
2 =
7,260
composite factor = 2
4 × 3
2 × 5 × 11 =
7,920
composite factor = 2
3 × 3
2 × 11
2 =
8,712
composite factor = 2
4 × 5 × 11
2 =
9,680
composite factor = 2 × 3
2 × 5 × 11
2 =
10,890
composite factor = 2
3 × 3 × 5 × 11
2 =
14,520
composite factor = 2
4 × 3
2 × 11
2 =
17,424
composite factor = 2
2 × 3
2 × 5 × 11
2 =
21,780
composite factor = 2
4 × 3 × 5 × 11
2 =
29,040
composite factor = 2
3 × 3
2 × 5 × 11
2 =
43,560
composite factor = 2
4 × 3
2 × 5 × 11
2 =
87,120
90 factors (divisors)
What times what is 87,120?
What number multiplied by what number equals 87,120?
All the combinations of any two natural numbers whose product equals 87,120.
1 × 87,120 = 87,120
2 × 43,560 = 87,120
3 × 29,040 = 87,120
4 × 21,780 = 87,120
5 × 17,424 = 87,120
6 × 14,520 = 87,120
8 × 10,890 = 87,120
9 × 9,680 = 87,120
10 × 8,712 = 87,120
11 × 7,920 = 87,120
12 × 7,260 = 87,120
15 × 5,808 = 87,120
16 × 5,445 = 87,120
18 × 4,840 = 87,120
20 × 4,356 = 87,120
22 × 3,960 = 87,120
24 × 3,630 = 87,120
30 × 2,904 = 87,120
33 × 2,640 = 87,120
36 × 2,420 = 87,120
40 × 2,178 = 87,120
44 × 1,980 = 87,120
45 × 1,936 = 87,120
48 × 1,815 = 87,120
55 × 1,584 = 87,120
60 × 1,452 = 87,120
66 × 1,320 = 87,120
72 × 1,210 = 87,120
80 × 1,089 = 87,120
88 × 990 = 87,120
90 × 968 = 87,120
99 × 880 = 87,120
110 × 792 = 87,120
120 × 726 = 87,120
121 × 720 = 87,120
132 × 660 = 87,120
144 × 605 = 87,120
165 × 528 = 87,120
176 × 495 = 87,120
180 × 484 = 87,120
198 × 440 = 87,120
220 × 396 = 87,120
240 × 363 = 87,120
242 × 360 = 87,120
264 × 330 = 87,120
45 unique multiplications The final answer:
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