Is 1005 a prime number?
No, 1005 is not a prime number. It is divisible by 3: 1005 = 3 × 335.
Is 1005 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 √1005 ≈ 31.70. If none of them divides 1005, it is prime.
- 3
3 divides 1005 exactly, so it is not prime. Its prime factorisation is
LaTeX source of the formulas on this page
\[ 1005 = 3 \times 5 \times 67 \]
Testing 1005 by the primes up to its square root
| Prime | Division | Result |
|---|---|---|
| 2 | 1005 ÷ 2 | leaves 1 |
| 3 | 1005 ÷ 3 | divides exactly (335) |
| 5 | 1005 ÷ 5 | divides exactly (201) |
| 7 | 1005 ÷ 7 | leaves 4 |
| 11 | 1005 ÷ 11 | leaves 4 |
| 13 | 1005 ÷ 13 | leaves 4 |
| 17 | 1005 ÷ 17 | leaves 2 |
| 19 | 1005 ÷ 19 | leaves 17 |
| 23 | 1005 ÷ 23 | leaves 16 |
| 29 | 1005 ÷ 29 | leaves 19 |
| 31 | 1005 ÷ 31 | leaves 13 |
Questions
Is 1005 a prime number?
No, 1005 is not a prime number. It is divisible by 3: 1005 = 3 × 335.
What is the next prime after 1005?
1009.
What is the prime number before 1005?
997.
What are the factors of 1005?
1, 3, 5, 15, 67, 201, 335, 1005.