Is 4991 a prime number?
No, 4991 is not a prime number. It is divisible by 7: 4991 = 7 × 713.
Is 4991 prime?
Pick any whole number from 1 to 10,000.
How to work it out
- 1
A prime number has exactly two factors: 1 and itself.
- 2
It is enough to test the primes up to √4991 ≈ 70.65. If none of them divides 4991, it is prime.
- 3
7 divides 4991 exactly, so it is not prime. Its prime factorisation is
LaTeX source of the formulas on this page
\[ 4991 = 7 \times 23 \times 31 \]
Testing 4991 by the primes up to its square root
| Prime | Division | Result |
|---|---|---|
| 2 | 4991 ÷ 2 | leaves 1 |
| 3 | 4991 ÷ 3 | leaves 2 |
| 5 | 4991 ÷ 5 | leaves 1 |
| 7 | 4991 ÷ 7 | divides exactly (713) |
| 11 | 4991 ÷ 11 | leaves 8 |
| 13 | 4991 ÷ 13 | leaves 12 |
| 17 | 4991 ÷ 17 | leaves 10 |
| 19 | 4991 ÷ 19 | leaves 13 |
| 23 | 4991 ÷ 23 | divides exactly (217) |
| 29 | 4991 ÷ 29 | leaves 3 |
| 31 | 4991 ÷ 31 | divides exactly (161) |
| 37 | 4991 ÷ 37 | leaves 33 |
Questions
Is 4991 a prime number?
No, 4991 is not a prime number. It is divisible by 7: 4991 = 7 × 713.
What is the next prime after 4991?
4993.
What is the prime number before 4991?
4987.
What are the factors of 4991?
1, 7, 23, 31, 161, 217, 713, 4991.