Factors of 991
The factors of 991 are 1, 991. It has 2 factors.
Factors of 991
Pick any whole number from 1 to 10,000.
How to work it out
- 1
A factor of 991 is a whole number that divides it with nothing left over. You only need to test the numbers up to √991 ≈ 31.48; every one that divides gives a pair.
- 2
The factor pairs are listed in the table below. Together they give 2 factors.
- 3
991 has no factors besides 1 and itself, so it is a prime number.
- 4
Add all the factors: 1 + 991 = 992. Without 991 itself that is 1, so 991 is a deficient number.
LaTeX source of the formulas on this page
\[ 991 = 991 \]
Factor pairs of 991
| Factor | Pairs with | Product |
|---|---|---|
| 1 | 991 | 1 × 991 = 991 |
Questions
What are the factors of 991?
The factors of 991 are 1, 991. It has 2 factors.
What are the prime factors of 991?
991. As a product: 991.
How many factors does 991 have?
991 has 2 factors (1 factor pair).
What is the sum of the factors of 991?
992.
Is 991 a prime number?
Yes. Its only factors are 1 and 991.