Is 423 a prime number?
No, 423 is not a prime number. It is divisible by 3: 423 = 3 × 141.
Is 423 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 √423 ≈ 20.57. If none of them divides 423, it is prime.
- 3
3 divides 423 exactly, so it is not prime. Its prime factorisation is
LaTeX source of the formulas on this page
\[ 423 = 3^{2} \times 47 \]Testing 423 by the primes up to its square root
| Prime | Division | Result |
|---|---|---|
| 2 | 423 ÷ 2 | leaves 1 |
| 3 | 423 ÷ 3 | divides exactly (141) |
| 5 | 423 ÷ 5 | leaves 3 |
| 7 | 423 ÷ 7 | leaves 3 |
| 11 | 423 ÷ 11 | leaves 5 |
| 13 | 423 ÷ 13 | leaves 7 |
| 17 | 423 ÷ 17 | leaves 15 |
| 19 | 423 ÷ 19 | leaves 5 |
Questions
Is 423 a prime number?
No, 423 is not a prime number. It is divisible by 3: 423 = 3 × 141.
What is the next prime after 423?
431.
What is the prime number before 423?
421.
What are the factors of 423?
1, 3, 9, 47, 141, 423.