What is the 7th prime number?
The 7th prime number is 17. The next prime is 19 (a gap of 2) and the one before is 13.
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 7th one is 17.
- 2
17 is prime because no prime up to ā17 ā 4.12 divides it.
- 3
The primes are spread thinner as numbers grow: by the prime number theorem the 7th prime is close to 7 Ć ln(7) ā 14, and here it is 17.
- 4
17 is a twin prime: 17 and 19 are both prime.
Primes around the 7th
| Position | Prime | Gap from the previous |
|---|---|---|
| 4 | 7 | 2 |
| 5 | 11 | 4 |
| 6 | 13 | 2 |
| 7 | 17 | 4 |
| 8 | 19 | 2 |
| 9 | 23 | 4 |
| 10 | 29 | 6 |
Questions
What is the 7th prime number?
17.
Which prime number is 17?
17 is the 7th prime number.
What is the sum of the first 7 primes?
58.