Factors of 400

2, 5. As a product: 2^4 × 5^2.

The factors of 400 are 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200, 400. It has 15 factors.

Factors of 400

Pick any whole number from 1 to 10,000.

400 = 2^{4} \times 5^{2}

How to work it out

1
A factor of 400 is a whole number that divides it with nothing left over. You only need to test the numbers up to √400 ≈ 20.00; every one that divides gives a pair.
2
The factor pairs are listed in the table below. Together they give 15 factors.
3
Prime factorisation: keep dividing by the smallest prime that fits.
$400 = 2^{4} \times 5^{2}$
4
Add all the factors: the sum is 961. Without 400 itself that is 561, so 400 is an abundant number.

LaTeX source of the formulas on this page

\[ 400 = 2^{4} \times 5^{2} \]

What are the factors of 400?

The factors of 400 are 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200, 400. It has 15 factors.

What are the prime factors of 400?

2, 5. As a product: $2^{4}$ × $5^{2}$ .

How many factors does 400 have?

400 has 15 factors (8 factor pairs, one of them 20 × 20).

What is the sum of the factors of 400?

961.

Is 400 a prime number?

No. It is divisible by 2, so 400 = 2 × 200.