Factors of 90
The factors of 90 are 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90. It has 12 factors.
Pick any whole number from 1 to 10,000.
How to work it out
- 1
A factor of 90 is a whole number that divides it with nothing left over. You only need to test the numbers up to √90 ≈ 9.49; every one that divides gives a pair.
- 2
The factor pairs are listed in the table below. Together they give 12 factors.
- 3
Prime factorisation: keep dividing by the smallest prime that fits.
- 4
Add all the factors: 1 + 2 + 3 + 5 + 6 + 9 + 10 + 15 + 18 + 30 + 45 + 90 = 234. Without 90 itself that is 144, so 90 is an abundant number.
LaTeX source of the formulas on this page
\[ 90 = 2 \times 3^{2} \times 5 \]Factor pairs of 90
| Factor | Pairs with | Product |
|---|---|---|
| 1 | 90 | 1 × 90 = 90 |
| 2 | 45 | 2 × 45 = 90 |
| 3 | 30 | 3 × 30 = 90 |
| 5 | 18 | 5 × 18 = 90 |
| 6 | 15 | 6 × 15 = 90 |
| 9 | 10 | 9 × 10 = 90 |
Questions
What are the factors of 90?
The factors of 90 are 1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90. It has 12 factors.
What are the prime factors of 90?
2, 3, 5. As a product: 2 × × 5.
How many factors does 90 have?
90 has 12 factors (6 factor pairs).
What is the sum of the factors of 90?
234.
Is 90 a prime number?
No. It is divisible by 2, so 90 = 2 × 45.