Is 999 a prime number?
No, 999 is not a prime number. It is divisible by 3: 999 = 3 × 333.
Is 999 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 √999 ≈ 31.61. If none of them divides 999, it is prime.
- 3
3 divides 999 exactly, so it is not prime. Its prime factorisation is
LaTeX source of the formulas on this page
\[ 999 = 3^{3} \times 37 \]Testing 999 by the primes up to its square root
| Prime | Division | Result |
|---|---|---|
| 2 | 999 ÷ 2 | leaves 1 |
| 3 | 999 ÷ 3 | divides exactly (333) |
| 5 | 999 ÷ 5 | leaves 4 |
| 7 | 999 ÷ 7 | leaves 5 |
| 11 | 999 ÷ 11 | leaves 9 |
| 13 | 999 ÷ 13 | leaves 11 |
| 17 | 999 ÷ 17 | leaves 13 |
| 19 | 999 ÷ 19 | leaves 11 |
| 23 | 999 ÷ 23 | leaves 10 |
| 29 | 999 ÷ 29 | leaves 13 |
| 31 | 999 ÷ 31 | leaves 7 |
Questions
Is 999 a prime number?
No, 999 is not a prime number. It is divisible by 3: 999 = 3 × 333.
What is the next prime after 999?
1009.
What is the prime number before 999?
997.
What are the factors of 999?
1, 3, 9, 27, 37, 111, 333, 999.