Factors of 45

The factors of 45 are 1, 3, 5, 9, 15, 45. It has 6 factors.

Factors of 45

Pick any whole number from 1 to 10,000.

45 = 3^{2} \times 5

How to work it out

1
A factor of 45 is a whole number that divides it with nothing left over. You only need to test the numbers up to √45 ≈ 6.71; 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.
$45 = 3^{2} \times 5$
4
Add all the factors: 1 + 3 + 5 + 9 + 15 + 45 = 78. Without 45 itself that is 33, so 45 is a deficient number.

LaTeX source of the formulas on this page

\[ 45 = 3^{2} \times 5 \]

What are the factors of 45?

The factors of 45 are 1, 3, 5, 9, 15, 45. It has 6 factors.

What are the prime factors of 45?

3, 5. As a product: $3^{2}$ × 5.

How many factors does 45 have?

45 has 6 factors (3 factor pairs).

What is the sum of the factors of 45?

78.

Is 45 a prime number?

No. It is divisible by 3, so 45 = 3 × 15.