What is the 668th prime number?
The 668th prime number is 4993. The next prime is 4999 (a gap of 6) and the one before is 4987.
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 668th one is 4993.
- 2
4993 is prime because no prime up to ā4993 ā 70.66 divides it.
- 3
The primes are spread thinner as numbers grow: by the prime number theorem the 668th prime is close to 668 Ć ln(668) ā 4345, and here it is 4993.
- 4
4993 has no twin: neither 4991 nor 4995 is prime.
Primes around the 668th
| Position | Prime | Gap from the previous |
|---|---|---|
| 665 | 4969 | 2 |
| 666 | 4973 | 4 |
| 667 | 4987 | 14 |
| 668 | 4993 | 6 |
| 669 | 4999 | 6 |
| 670 | 5003 | 4 |
| 671 | 5009 | 6 |
Questions
What is the 668th prime number?
4993.
Which prime number is 4993?
4993 is the 668th prime number.
What is the sum of the first 668 primes?
1,543,137.