Is 309 a prime number?
No, 309 is not a prime number. It is divisible by 3: 309 = 3 × 103.
Is 309 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 √309 ≈ 17.58. If none of them divides 309, it is prime.
- 3
3 divides 309 exactly, so it is not prime. Its prime factorisation is
LaTeX source of the formulas on this page
\[ 309 = 3 \times 103 \]
Testing 309 by the primes up to its square root
| Prime | Division | Result |
|---|---|---|
| 2 | 309 ÷ 2 | leaves 1 |
| 3 | 309 ÷ 3 | divides exactly (103) |
| 5 | 309 ÷ 5 | leaves 4 |
| 7 | 309 ÷ 7 | leaves 1 |
| 11 | 309 ÷ 11 | leaves 1 |
| 13 | 309 ÷ 13 | leaves 10 |
| 17 | 309 ÷ 17 | leaves 3 |
Questions
Is 309 a prime number?
No, 309 is not a prime number. It is divisible by 3: 309 = 3 × 103.
What is the next prime after 309?
311.
What is the prime number before 309?
307.
What are the factors of 309?
1, 3, 103, 309.