To find all the divisors of the number 72,240:
- 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 72,240:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
72,240 = 24 × 3 × 5 × 7 × 43
72,240 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 72,240
- 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
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
3 × 3 =
24
composite factor = 2
2 × 7 =
28
composite factor = 2 × 3 × 5 =
30
composite factor = 5 × 7 =
35
composite factor = 2
3 × 5 =
40
composite factor = 2 × 3 × 7 =
42
prime factor =
43
composite factor = 2
4 × 3 =
48
composite factor = 2
3 × 7 =
56
composite factor = 2
2 × 3 × 5 =
60
composite factor = 2 × 5 × 7 =
70
composite factor = 2
4 × 5 =
80
composite factor = 2
2 × 3 × 7 =
84
composite factor = 2 × 43 =
86
composite factor = 3 × 5 × 7 =
105
composite factor = 2
4 × 7 =
112
composite factor = 2
3 × 3 × 5 =
120
composite factor = 3 × 43 =
129
composite factor = 2
2 × 5 × 7 =
140
composite factor = 2
3 × 3 × 7 =
168
composite factor = 2
2 × 43 =
172
composite factor = 2 × 3 × 5 × 7 =
210
composite factor = 5 × 43 =
215
composite factor = 2
4 × 3 × 5 =
240
composite factor = 2 × 3 × 43 =
258
This list continues below...
... This list continues from above
composite factor = 2
3 × 5 × 7 =
280
composite factor = 7 × 43 =
301
composite factor = 2
4 × 3 × 7 =
336
composite factor = 2
3 × 43 =
344
composite factor = 2
2 × 3 × 5 × 7 =
420
composite factor = 2 × 5 × 43 =
430
composite factor = 2
2 × 3 × 43 =
516
composite factor = 2
4 × 5 × 7 =
560
composite factor = 2 × 7 × 43 =
602
composite factor = 3 × 5 × 43 =
645
composite factor = 2
4 × 43 =
688
composite factor = 2
3 × 3 × 5 × 7 =
840
composite factor = 2
2 × 5 × 43 =
860
composite factor = 3 × 7 × 43 =
903
composite factor = 2
3 × 3 × 43 =
1,032
composite factor = 2
2 × 7 × 43 =
1,204
composite factor = 2 × 3 × 5 × 43 =
1,290
composite factor = 5 × 7 × 43 =
1,505
composite factor = 2
4 × 3 × 5 × 7 =
1,680
composite factor = 2
3 × 5 × 43 =
1,720
composite factor = 2 × 3 × 7 × 43 =
1,806
composite factor = 2
4 × 3 × 43 =
2,064
composite factor = 2
3 × 7 × 43 =
2,408
composite factor = 2
2 × 3 × 5 × 43 =
2,580
composite factor = 2 × 5 × 7 × 43 =
3,010
composite factor = 2
4 × 5 × 43 =
3,440
composite factor = 2
2 × 3 × 7 × 43 =
3,612
composite factor = 3 × 5 × 7 × 43 =
4,515
composite factor = 2
4 × 7 × 43 =
4,816
composite factor = 2
3 × 3 × 5 × 43 =
5,160
composite factor = 2
2 × 5 × 7 × 43 =
6,020
composite factor = 2
3 × 3 × 7 × 43 =
7,224
composite factor = 2 × 3 × 5 × 7 × 43 =
9,030
composite factor = 2
4 × 3 × 5 × 43 =
10,320
composite factor = 2
3 × 5 × 7 × 43 =
12,040
composite factor = 2
4 × 3 × 7 × 43 =
14,448
composite factor = 2
2 × 3 × 5 × 7 × 43 =
18,060
composite factor = 2
4 × 5 × 7 × 43 =
24,080
composite factor = 2
3 × 3 × 5 × 7 × 43 =
36,120
composite factor = 2
4 × 3 × 5 × 7 × 43 =
72,240
80 factors (divisors)
What times what is 72,240?
What number multiplied by what number equals 72,240?
All the combinations of any two natural numbers whose product equals 72,240.
1 × 72,240 = 72,240
2 × 36,120 = 72,240
3 × 24,080 = 72,240
4 × 18,060 = 72,240
5 × 14,448 = 72,240
6 × 12,040 = 72,240
7 × 10,320 = 72,240
8 × 9,030 = 72,240
10 × 7,224 = 72,240
12 × 6,020 = 72,240
14 × 5,160 = 72,240
15 × 4,816 = 72,240
16 × 4,515 = 72,240
20 × 3,612 = 72,240
21 × 3,440 = 72,240
24 × 3,010 = 72,240
28 × 2,580 = 72,240
30 × 2,408 = 72,240
35 × 2,064 = 72,240
40 × 1,806 = 72,240
42 × 1,720 = 72,240
43 × 1,680 = 72,240
48 × 1,505 = 72,240
56 × 1,290 = 72,240
60 × 1,204 = 72,240
70 × 1,032 = 72,240
80 × 903 = 72,240
84 × 860 = 72,240
86 × 840 = 72,240
105 × 688 = 72,240
112 × 645 = 72,240
120 × 602 = 72,240
129 × 560 = 72,240
140 × 516 = 72,240
168 × 430 = 72,240
172 × 420 = 72,240
210 × 344 = 72,240
215 × 336 = 72,240
240 × 301 = 72,240
258 × 280 = 72,240
40 unique multiplications The final answer:
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