To find all the divisors of the number 72,800:
- 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 72,800:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
72,800 = 25 × 52 × 7 × 13
72,800 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) × (2 + 1) × (1 + 1) × (1 + 1) = 6 × 3 × 2 × 2 = 72
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 72,800
- 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
composite factor = 2
2 =
4
prime factor =
5
prime factor =
7
composite factor = 2
3 =
8
composite factor = 2 × 5 =
10
prime factor =
13
composite factor = 2 × 7 =
14
composite factor = 2
4 =
16
composite factor = 2
2 × 5 =
20
composite factor = 5
2 =
25
composite factor = 2 × 13 =
26
composite factor = 2
2 × 7 =
28
composite factor = 2
5 =
32
composite factor = 5 × 7 =
35
composite factor = 2
3 × 5 =
40
composite factor = 2 × 5
2 =
50
composite factor = 2
2 × 13 =
52
composite factor = 2
3 × 7 =
56
composite factor = 5 × 13 =
65
composite factor = 2 × 5 × 7 =
70
composite factor = 2
4 × 5 =
80
composite factor = 7 × 13 =
91
composite factor = 2
2 × 5
2 =
100
composite factor = 2
3 × 13 =
104
composite factor = 2
4 × 7 =
112
composite factor = 2 × 5 × 13 =
130
composite factor = 2
2 × 5 × 7 =
140
composite factor = 2
5 × 5 =
160
composite factor = 5
2 × 7 =
175
composite factor = 2 × 7 × 13 =
182
composite factor = 2
3 × 5
2 =
200
composite factor = 2
4 × 13 =
208
composite factor = 2
5 × 7 =
224
composite factor = 2
2 × 5 × 13 =
260
This list continues below...
... This list continues from above
composite factor = 2
3 × 5 × 7 =
280
composite factor = 5
2 × 13 =
325
composite factor = 2 × 5
2 × 7 =
350
composite factor = 2
2 × 7 × 13 =
364
composite factor = 2
4 × 5
2 =
400
composite factor = 2
5 × 13 =
416
composite factor = 5 × 7 × 13 =
455
composite factor = 2
3 × 5 × 13 =
520
composite factor = 2
4 × 5 × 7 =
560
composite factor = 2 × 5
2 × 13 =
650
composite factor = 2
2 × 5
2 × 7 =
700
composite factor = 2
3 × 7 × 13 =
728
composite factor = 2
5 × 5
2 =
800
composite factor = 2 × 5 × 7 × 13 =
910
composite factor = 2
4 × 5 × 13 =
1,040
composite factor = 2
5 × 5 × 7 =
1,120
composite factor = 2
2 × 5
2 × 13 =
1,300
composite factor = 2
3 × 5
2 × 7 =
1,400
composite factor = 2
4 × 7 × 13 =
1,456
composite factor = 2
2 × 5 × 7 × 13 =
1,820
composite factor = 2
5 × 5 × 13 =
2,080
composite factor = 5
2 × 7 × 13 =
2,275
composite factor = 2
3 × 5
2 × 13 =
2,600
composite factor = 2
4 × 5
2 × 7 =
2,800
composite factor = 2
5 × 7 × 13 =
2,912
composite factor = 2
3 × 5 × 7 × 13 =
3,640
composite factor = 2 × 5
2 × 7 × 13 =
4,550
composite factor = 2
4 × 5
2 × 13 =
5,200
composite factor = 2
5 × 5
2 × 7 =
5,600
composite factor = 2
4 × 5 × 7 × 13 =
7,280
composite factor = 2
2 × 5
2 × 7 × 13 =
9,100
composite factor = 2
5 × 5
2 × 13 =
10,400
composite factor = 2
5 × 5 × 7 × 13 =
14,560
composite factor = 2
3 × 5
2 × 7 × 13 =
18,200
composite factor = 2
4 × 5
2 × 7 × 13 =
36,400
composite factor = 2
5 × 5
2 × 7 × 13 =
72,800
72 factors (divisors)
What times what is 72,800?
What number multiplied by what number equals 72,800?
All the combinations of any two natural numbers whose product equals 72,800.
1 × 72,800 = 72,800
2 × 36,400 = 72,800
4 × 18,200 = 72,800
5 × 14,560 = 72,800
7 × 10,400 = 72,800
8 × 9,100 = 72,800
10 × 7,280 = 72,800
13 × 5,600 = 72,800
14 × 5,200 = 72,800
16 × 4,550 = 72,800
20 × 3,640 = 72,800
25 × 2,912 = 72,800
26 × 2,800 = 72,800
28 × 2,600 = 72,800
32 × 2,275 = 72,800
35 × 2,080 = 72,800
40 × 1,820 = 72,800
50 × 1,456 = 72,800
52 × 1,400 = 72,800
56 × 1,300 = 72,800
65 × 1,120 = 72,800
70 × 1,040 = 72,800
80 × 910 = 72,800
91 × 800 = 72,800
100 × 728 = 72,800
104 × 700 = 72,800
112 × 650 = 72,800
130 × 560 = 72,800
140 × 520 = 72,800
160 × 455 = 72,800
175 × 416 = 72,800
182 × 400 = 72,800
200 × 364 = 72,800
208 × 350 = 72,800
224 × 325 = 72,800
260 × 280 = 72,800
36 unique multiplications The final answer:
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