Is 1998 a prime number?
No, 1998 is not a prime number. It is divisible by 2: 1998 = 2 × 999.
Is 1998 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 √1998 ≈ 44.70. If none of them divides 1998, it is prime.
- 3
2 divides 1998 exactly, so it is not prime. Its prime factorisation is
LaTeX source of the formulas on this page
\[ 1998 = 2 \times 3^{3} \times 37 \]Testing 1998 by the primes up to its square root
| Prime | Division | Result |
|---|---|---|
| 2 | 1998 ÷ 2 | divides exactly (999) |
| 3 | 1998 ÷ 3 | divides exactly (666) |
| 5 | 1998 ÷ 5 | leaves 3 |
| 7 | 1998 ÷ 7 | leaves 3 |
| 11 | 1998 ÷ 11 | leaves 7 |
| 13 | 1998 ÷ 13 | leaves 9 |
| 17 | 1998 ÷ 17 | leaves 9 |
| 19 | 1998 ÷ 19 | leaves 3 |
| 23 | 1998 ÷ 23 | leaves 20 |
| 29 | 1998 ÷ 29 | leaves 26 |
| 31 | 1998 ÷ 31 | leaves 14 |
| 37 | 1998 ÷ 37 | divides exactly (54) |
Questions
Is 1998 a prime number?
No, 1998 is not a prime number. It is divisible by 2: 1998 = 2 × 999.
What is the next prime after 1998?
1999.
What is the prime number before 1998?
1997.
What are the factors of 1998?
1, 2, 3, 6, 9, 18, 27, 37, 54, 74, 111, 222, 333, 666, 999, 1998.