What is the 8th prime number?
The 8th prime number is 19. The next prime is 23 (a gap of 4) and the one before is 17.
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 8th one is 19.
- 2
19 is prime because no prime up to ā19 ā 4.36 divides it.
- 3
The primes are spread thinner as numbers grow: by the prime number theorem the 8th prime is close to 8 Ć ln(8) ā 17, and here it is 19.
- 4
19 is a twin prime: 17 and 19 are both prime.
Primes around the 8th
| Position | Prime | Gap from the previous |
|---|---|---|
| 5 | 11 | 4 |
| 6 | 13 | 2 |
| 7 | 17 | 4 |
| 8 | 19 | 2 |
| 9 | 23 | 4 |
| 10 | 29 | 6 |
| 11 | 31 | 2 |
Questions
What is the 8th prime number?
19.
Which prime number is 19?
19 is the 8th prime number.
What is the sum of the first 8 primes?
77.