Factors of 20

The factors of 20 are 1, 2, 4, 5, 10, 20. It has 6 factors.

Factors of 20

Pick any whole number from 1 to 10,000.

20 = 2^{2} \times 5

How to work it out

1
A factor of 20 is a whole number that divides it with nothing left over. You only need to test the numbers up to √20 ≈ 4.47; every one that divides gives a pair.
2
The factor pairs are listed in the table below. Together they give 6 factors.
3
Prime factorisation: keep dividing by the smallest prime that fits.
$20 = 2^{2} \times 5$
4
Add all the factors: 1 + 2 + 4 + 5 + 10 + 20 = 42. Without 20 itself that is 22, so 20 is an abundant number.

LaTeX source of the formulas on this page

\[ 20 = 2^{2} \times 5 \]

What are the factors of 20?

The factors of 20 are 1, 2, 4, 5, 10, 20. It has 6 factors.

What are the prime factors of 20?

2, 5. As a product: $2^{2}$ × 5.

How many factors does 20 have?

20 has 6 factors (3 factor pairs).

What is the sum of the factors of 20?

42.

Is 20 a prime number?

No. It is divisible by 2, so 20 = 2 × 10.