Is 1990 a prime number?
No, 1990 is not a prime number. It is divisible by 2: 1990 = 2 × 995.
Is 1990 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 √1990 ≈ 44.61. If none of them divides 1990, it is prime.
- 3
2 divides 1990 exactly, so it is not prime. Its prime factorisation is
LaTeX source of the formulas on this page
\[ 1990 = 2 \times 5 \times 199 \]
Testing 1990 by the primes up to its square root
| Prime | Division | Result |
|---|---|---|
| 2 | 1990 ÷ 2 | divides exactly (995) |
| 3 | 1990 ÷ 3 | leaves 1 |
| 5 | 1990 ÷ 5 | divides exactly (398) |
| 7 | 1990 ÷ 7 | leaves 2 |
| 11 | 1990 ÷ 11 | leaves 10 |
| 13 | 1990 ÷ 13 | leaves 1 |
| 17 | 1990 ÷ 17 | leaves 1 |
| 19 | 1990 ÷ 19 | leaves 14 |
| 23 | 1990 ÷ 23 | leaves 12 |
| 29 | 1990 ÷ 29 | leaves 18 |
| 31 | 1990 ÷ 31 | leaves 6 |
| 37 | 1990 ÷ 37 | leaves 29 |
Questions
Is 1990 a prime number?
No, 1990 is not a prime number. It is divisible by 2: 1990 = 2 × 995.
What is the next prime after 1990?
1993.
What is the prime number before 1990?
1987.
What are the factors of 1990?
1, 2, 5, 10, 199, 398, 995, 1990.