What is the 640th prime number?
The 640th prime number is 4751. The next prime is 4759 (a gap of 8) and the one before is 4733.
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 640th one is 4751.
- 2
4751 is prime because no prime up to ā4751 ā 68.93 divides it.
- 3
The primes are spread thinner as numbers grow: by the prime number theorem the 640th prime is close to 640 Ć ln(640) ā 4135, and here it is 4751.
- 4
4751 has no twin: neither 4749 nor 4753 is prime.
Primes around the 640th
| Position | Prime | Gap from the previous |
|---|---|---|
| 637 | 4723 | 2 |
| 638 | 4729 | 6 |
| 639 | 4733 | 4 |
| 640 | 4751 | 18 |
| 641 | 4759 | 8 |
| 642 | 4783 | 24 |
| 643 | 4787 | 4 |
Questions
What is the 640th prime number?
4751.
Which prime number is 4751?
4751 is the 640th prime number.
What is the sum of the first 640 primes?
1,406,395.