Is 40 a prime number?
No, 40 is not a prime number. It is divisible by 2: 40 = 2 × 20.
Is 40 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 √40 ≈ 6.32. If none of them divides 40, it is prime.
- 3
2 divides 40 exactly, so it is not prime. Its prime factorisation is
LaTeX source of the formulas on this page
\[ 40 = 2^{3} \times 5 \]Testing 40 by the primes up to its square root
| Prime | Division | Result |
|---|---|---|
| 2 | 40 ÷ 2 | divides exactly (20) |
| 3 | 40 ÷ 3 | leaves 1 |
| 5 | 40 ÷ 5 | divides exactly (8) |
Questions
Is 40 a prime number?
No, 40 is not a prime number. It is divisible by 2: 40 = 2 × 20.
What is the next prime after 40?
41.
What is the prime number before 40?
37.
What are the factors of 40?
1, 2, 4, 5, 8, 10, 20, 40.