Is 1240 a prime number?
No, 1240 is not a prime number. It is divisible by 2: 1240 = 2 × 620.
Is 1240 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 √1240 ≈ 35.21. If none of them divides 1240, it is prime.
- 3
2 divides 1240 exactly, so it is not prime. Its prime factorisation is
LaTeX source of the formulas on this page
\[ 1240 = 2^{3} \times 5 \times 31 \]Testing 1240 by the primes up to its square root
| Prime | Division | Result |
|---|---|---|
| 2 | 1240 ÷ 2 | divides exactly (620) |
| 3 | 1240 ÷ 3 | leaves 1 |
| 5 | 1240 ÷ 5 | divides exactly (248) |
| 7 | 1240 ÷ 7 | leaves 1 |
| 11 | 1240 ÷ 11 | leaves 8 |
| 13 | 1240 ÷ 13 | leaves 5 |
| 17 | 1240 ÷ 17 | leaves 16 |
| 19 | 1240 ÷ 19 | leaves 5 |
| 23 | 1240 ÷ 23 | leaves 21 |
| 29 | 1240 ÷ 29 | leaves 22 |
| 31 | 1240 ÷ 31 | divides exactly (40) |
Questions
Is 1240 a prime number?
No, 1240 is not a prime number. It is divisible by 2: 1240 = 2 × 620.
What is the next prime after 1240?
1249.
What is the prime number before 1240?
1237.
What are the factors of 1240?
1, 2, 4, 5, 8, 10, 20, 31, 40, 62, 124, 155, 248, 310, 620, 1240.