To find all the divisors of the number 25,188,880:
- 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 25,188,880:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
25,188,880 = 24 × 5 × 179 × 1,759
25,188,880 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) = 5 × 2 × 2 × 2 = 40
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 25,188,880
- 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
composite factor = 2
3 =
8
composite factor = 2 × 5 =
10
composite factor = 2
4 =
16
composite factor = 2
2 × 5 =
20
composite factor = 2
3 × 5 =
40
composite factor = 2
4 × 5 =
80
prime factor =
179
composite factor = 2 × 179 =
358
composite factor = 2
2 × 179 =
716
composite factor = 5 × 179 =
895
composite factor = 2
3 × 179 =
1,432
prime factor =
1,759
composite factor = 2 × 5 × 179 =
1,790
composite factor = 2
4 × 179 =
2,864
composite factor = 2 × 1,759 =
3,518
composite factor = 2
2 × 5 × 179 =
3,580
This list continues below...
... This list continues from above
composite factor = 2
2 × 1,759 =
7,036
composite factor = 2
3 × 5 × 179 =
7,160
composite factor = 5 × 1,759 =
8,795
composite factor = 2
3 × 1,759 =
14,072
composite factor = 2
4 × 5 × 179 =
14,320
composite factor = 2 × 5 × 1,759 =
17,590
composite factor = 2
4 × 1,759 =
28,144
composite factor = 2
2 × 5 × 1,759 =
35,180
composite factor = 2
3 × 5 × 1,759 =
70,360
composite factor = 2
4 × 5 × 1,759 =
140,720
composite factor = 179 × 1,759 =
314,861
composite factor = 2 × 179 × 1,759 =
629,722
composite factor = 2
2 × 179 × 1,759 =
1,259,444
composite factor = 5 × 179 × 1,759 =
1,574,305
composite factor = 2
3 × 179 × 1,759 =
2,518,888
composite factor = 2 × 5 × 179 × 1,759 =
3,148,610
composite factor = 2
4 × 179 × 1,759 =
5,037,776
composite factor = 2
2 × 5 × 179 × 1,759 =
6,297,220
composite factor = 2
3 × 5 × 179 × 1,759 =
12,594,440
composite factor = 2
4 × 5 × 179 × 1,759 =
25,188,880
40 factors (divisors)
What times what is 25,188,880?
What number multiplied by what number equals 25,188,880?
All the combinations of any two natural numbers whose product equals 25,188,880.
1 × 25,188,880 = 25,188,880
2 × 12,594,440 = 25,188,880
4 × 6,297,220 = 25,188,880
5 × 5,037,776 = 25,188,880
8 × 3,148,610 = 25,188,880
10 × 2,518,888 = 25,188,880
16 × 1,574,305 = 25,188,880
20 × 1,259,444 = 25,188,880
40 × 629,722 = 25,188,880
80 × 314,861 = 25,188,880
179 × 140,720 = 25,188,880
358 × 70,360 = 25,188,880
716 × 35,180 = 25,188,880
895 × 28,144 = 25,188,880
1,432 × 17,590 = 25,188,880
1,759 × 14,320 = 25,188,880
1,790 × 14,072 = 25,188,880
2,864 × 8,795 = 25,188,880
3,518 × 7,160 = 25,188,880
3,580 × 7,036 = 25,188,880
20 unique multiplications The final answer:
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