What is the 79th prime number?
The 79th prime number is 401. The next prime is 409 (a gap of 8) and the one before is 397.
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 79th one is 401.
- 2
401 is prime because no prime up to ā401 ā 20.02 divides it.
- 3
The primes are spread thinner as numbers grow: by the prime number theorem the 79th prime is close to 79 Ć ln(79) ā 345, and here it is 401.
- 4
401 has no twin: neither 399 nor 403 is prime.
Primes around the 79th
| Position | Prime | Gap from the previous |
|---|---|---|
| 76 | 383 | 4 |
| 77 | 389 | 6 |
| 78 | 397 | 8 |
| 79 | 401 | 4 |
| 80 | 409 | 8 |
| 81 | 419 | 10 |
| 82 | 421 | 2 |
Questions
What is the 79th prime number?
401.
Which prime number is 401?
401 is the 79th prime number.
What is the sum of the first 79 primes?
14,288.