What is the 390th prime number?
The 390th prime number is 2687. The next prime is 2689 (a gap of 2) and the one before is 2683.
Position
Pick any whole number from 1 to 10,000.
How to work it out
- 1
List the primes in order: 2, 3, 5, 7, 11, 13, ā¦ The 390th one is 2687.
- 2
2687 is prime because no prime up to ā2687 ā 51.84 divides it.
- 3
The primes are spread thinner as numbers grow: by the prime number theorem the 390th prime is close to 390 Ć ln(390) ā 2327, and here it is 2687.
- 4
2687 is a twin prime: 2687 and 2689 are both prime.
Primes around the 390th
| Position | Prime | Gap from the previous |
|---|---|---|
| 387 | 2671 | 8 |
| 388 | 2677 | 6 |
| 389 | 2683 | 6 |
| 390 | 2687 | 4 |
| 391 | 2689 | 2 |
| 392 | 2693 | 4 |
| 393 | 2699 | 6 |
Questions
What is the 390th prime number?
2687.
Which prime number is 2687?
2687 is the 390th prime number.
What is the sum of the first 390 primes?
480,693.