Factors of 20
There are 6 factors of 20 — the full list is below, with factor pairs, prime factorization, and divisibility notes.
Factors of 20
1, 2, 4, 5, 10, 20
Factor pairs of 20
- 1 × 20
- 2 × 10
- 4 × 5
Prime factorization of 20
20 = 2² × 5
Number facts
- 20 is a composite number.
- 20 has 6 factors.
- 20 is not a perfect square.
- The sum of all factors of 20 is 42.
Divisibility rules that apply to 20
- 20 is divisible by 2 because it ends in an even digit (0, 2, 4, 6, or 8).
- 20 is divisible by 5 because it ends in 0 or 5.
- 20 is divisible by 10 because it ends in 0.
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How the factors of 20 are calculated
To find the factors of 20, every whole number from 1 up to the square root of 20(about 4.47) is tested for even division. 20 is even, and it divides evenly by 2, 4, 5, 10. Written as a product of primes, 20 = 2² × 5, which confirms every factor above is a combination of those prime building blocks.
Frequently asked questions about 20
How many factors does 20 have?
20 has 6 factors: 1, 2, 4, 5, 10, 20.
Is 20 a prime number?
No. 20 is composite because it has factors other than 1 and itself.
What are the factor pairs of 20?
The factor pairs of 20 are 1 × 20, 2 × 10, 4 × 5.
What is the prime factorization of 20?
The prime factorization of 20 is 2² × 5.