To find all the divisors of the number 20,199,620:
- 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 20,199,620:
The prime factorization of a number: finding the prime numbers that multiply together to make that number.
20,199,620 = 22 × 5 × 7 × 157 × 919
20,199,620 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 = (2 + 1) × (1 + 1) × (1 + 1) × (1 + 1) × (1 + 1) = 3 × 2 × 2 × 2 × 2 = 48
But to actually calculate the factors, see below...
2. Multiply the prime factors of the number 20,199,620
- 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 × 5 =
10
composite factor = 2 × 7 =
14
composite factor = 2
2 × 5 =
20
composite factor = 2
2 × 7 =
28
composite factor = 5 × 7 =
35
composite factor = 2 × 5 × 7 =
70
composite factor = 2
2 × 5 × 7 =
140
prime factor =
157
composite factor = 2 × 157 =
314
composite factor = 2
2 × 157 =
628
composite factor = 5 × 157 =
785
prime factor =
919
composite factor = 7 × 157 =
1,099
composite factor = 2 × 5 × 157 =
1,570
composite factor = 2 × 919 =
1,838
composite factor = 2 × 7 × 157 =
2,198
composite factor = 2
2 × 5 × 157 =
3,140
composite factor = 2
2 × 919 =
3,676
composite factor = 2
2 × 7 × 157 =
4,396
This list continues below...
... This list continues from above
composite factor = 5 × 919 =
4,595
composite factor = 5 × 7 × 157 =
5,495
composite factor = 7 × 919 =
6,433
composite factor = 2 × 5 × 919 =
9,190
composite factor = 2 × 5 × 7 × 157 =
10,990
composite factor = 2 × 7 × 919 =
12,866
composite factor = 2
2 × 5 × 919 =
18,380
composite factor = 2
2 × 5 × 7 × 157 =
21,980
composite factor = 2
2 × 7 × 919 =
25,732
composite factor = 5 × 7 × 919 =
32,165
composite factor = 2 × 5 × 7 × 919 =
64,330
composite factor = 2
2 × 5 × 7 × 919 =
128,660
composite factor = 157 × 919 =
144,283
composite factor = 2 × 157 × 919 =
288,566
composite factor = 2
2 × 157 × 919 =
577,132
composite factor = 5 × 157 × 919 =
721,415
composite factor = 7 × 157 × 919 =
1,009,981
composite factor = 2 × 5 × 157 × 919 =
1,442,830
composite factor = 2 × 7 × 157 × 919 =
2,019,962
composite factor = 2
2 × 5 × 157 × 919 =
2,885,660
composite factor = 2
2 × 7 × 157 × 919 =
4,039,924
composite factor = 5 × 7 × 157 × 919 =
5,049,905
composite factor = 2 × 5 × 7 × 157 × 919 =
10,099,810
composite factor = 2
2 × 5 × 7 × 157 × 919 =
20,199,620
48 factors (divisors)
What times what is 20,199,620?
What number multiplied by what number equals 20,199,620?
All the combinations of any two natural numbers whose product equals 20,199,620.
1 × 20,199,620 = 20,199,620
2 × 10,099,810 = 20,199,620
4 × 5,049,905 = 20,199,620
5 × 4,039,924 = 20,199,620
7 × 2,885,660 = 20,199,620
10 × 2,019,962 = 20,199,620
14 × 1,442,830 = 20,199,620
20 × 1,009,981 = 20,199,620
28 × 721,415 = 20,199,620
35 × 577,132 = 20,199,620
70 × 288,566 = 20,199,620
140 × 144,283 = 20,199,620
157 × 128,660 = 20,199,620
314 × 64,330 = 20,199,620
628 × 32,165 = 20,199,620
785 × 25,732 = 20,199,620
919 × 21,980 = 20,199,620
1,099 × 18,380 = 20,199,620
1,570 × 12,866 = 20,199,620
1,838 × 10,990 = 20,199,620
2,198 × 9,190 = 20,199,620
3,140 × 6,433 = 20,199,620
3,676 × 5,495 = 20,199,620
4,396 × 4,595 = 20,199,620
24 unique multiplications The final answer:
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