Is 2021 a prime number?
No, 2021 is not a prime number. It is divisible by 43: 2021 = 43 × 47.
Is 2021 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 √2021 ≈ 44.96. If none of them divides 2021, it is prime.
- 3
43 divides 2021 exactly, so it is not prime. Its prime factorisation is
LaTeX source of the formulas on this page
\[ 2021 = 43 \times 47 \]
Testing 2021 by the primes up to its square root
| Prime | Division | Result |
|---|---|---|
| 2 | 2021 ÷ 2 | leaves 1 |
| 3 | 2021 ÷ 3 | leaves 2 |
| 5 | 2021 ÷ 5 | leaves 1 |
| 7 | 2021 ÷ 7 | leaves 5 |
| 11 | 2021 ÷ 11 | leaves 8 |
| 13 | 2021 ÷ 13 | leaves 6 |
| 17 | 2021 ÷ 17 | leaves 15 |
| 19 | 2021 ÷ 19 | leaves 7 |
| 23 | 2021 ÷ 23 | leaves 20 |
| 29 | 2021 ÷ 29 | leaves 20 |
| 31 | 2021 ÷ 31 | leaves 6 |
| 37 | 2021 ÷ 37 | leaves 23 |
Questions
Is 2021 a prime number?
No, 2021 is not a prime number. It is divisible by 43: 2021 = 43 × 47.
What is the next prime after 2021?
2027.
What is the prime number before 2021?
2017.
What are the factors of 2021?
1, 43, 47, 2021.