Factors of 840
The factors of 840 are 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 20, 21, 24, 28, 30, 35, 40, 42, 56, 60, 70, 84, 105, 120, 140, 168, 210, 280, 420, 840. It has 32 factors.
Pick any whole number from 1 to 10,000.
How to work it out
- 1
A factor of 840 is a whole number that divides it with nothing left over. You only need to test the numbers up to √840 ≈ 28.98; every one that divides gives a pair.
- 2
The factor pairs are listed in the table below. Together they give 32 factors.
- 3
Prime factorisation: keep dividing by the smallest prime that fits.
- 4
Add all the factors: the sum is 2880. Without 840 itself that is 2040, so 840 is an abundant number.
LaTeX source of the formulas on this page
\[ 840 = 2^{3} \times 3 \times 5 \times 7 \]Factor pairs of 840
| Factor | Pairs with | Product |
|---|---|---|
| 1 | 840 | 1 × 840 = 840 |
| 2 | 420 | 2 × 420 = 840 |
| 3 | 280 | 3 × 280 = 840 |
| 4 | 210 | 4 × 210 = 840 |
| 5 | 168 | 5 × 168 = 840 |
| 6 | 140 | 6 × 140 = 840 |
| 7 | 120 | 7 × 120 = 840 |
| 8 | 105 | 8 × 105 = 840 |
| 10 | 84 | 10 × 84 = 840 |
| 12 | 70 | 12 × 70 = 840 |
| 14 | 60 | 14 × 60 = 840 |
| 15 | 56 | 15 × 56 = 840 |
| 20 | 42 | 20 × 42 = 840 |
| 21 | 40 | 21 × 40 = 840 |
| 24 | 35 | 24 × 35 = 840 |
| 28 | 30 | 28 × 30 = 840 |
Questions
What are the factors of 840?
The factors of 840 are 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 15, 20, 21, 24, 28, 30, 35, 40, 42, 56, 60, 70, 84, 105, 120, 140, 168, 210, 280, 420, 840. It has 32 factors.
What are the prime factors of 840?
2, 3, 5, 7. As a product: × 3 × 5 × 7.
How many factors does 840 have?
840 has 32 factors (16 factor pairs).
What is the sum of the factors of 840?
2880.
Is 840 a prime number?
No. It is divisible by 2, so 840 = 2 × 420.