Factors of 40

The factors of 40 are 1, 2, 4, 5, 8, 10, 20, 40. It has 8 factors.

Factors of 40

Pick any whole number from 1 to 10,000.

40 = 2^{3} \times 5

How to work it out

1
A factor of 40 is a whole number that divides it with nothing left over. You only need to test the numbers up to √40 ≈ 6.32; every one that divides gives a pair.
2
The factor pairs are listed in the table below. Together they give 8 factors.
3
Prime factorisation: keep dividing by the smallest prime that fits.
$40 = 2^{3} \times 5$
4
Add all the factors: 1 + 2 + 4 + 5 + 8 + 10 + 20 + 40 = 90. Without 40 itself that is 50, so 40 is an abundant number.

LaTeX source of the formulas on this page

\[ 40 = 2^{3} \times 5 \]

What are the factors of 40?

The factors of 40 are 1, 2, 4, 5, 8, 10, 20, 40. It has 8 factors.

What are the prime factors of 40?

2, 5. As a product: $2^{3}$ × 5.

How many factors does 40 have?

40 has 8 factors (4 factor pairs).

What is the sum of the factors of 40?

90.

Is 40 a prime number?

No. It is divisible by 2, so 40 = 2 × 20.