What is the 1981st prime number?
The 1981st prime number is 17203. The next prime is 17207 (a gap of 4) and the one before is 17191.
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 1981st one is 17203.
- 2
17203 is prime because no prime up to ā17203 ā 131.16 divides it.
- 3
The primes are spread thinner as numbers grow: by the prime number theorem the 1981st prime is close to 1981 Ć ln(1981) ā 15038, and here it is 17203.
- 4
17203 has no twin: neither 17201 nor 17205 is prime.
Primes around the 1981st
| Position | Prime | Gap from the previous |
|---|---|---|
| 1978 | 17183 | 16 |
| 1979 | 17189 | 6 |
| 1980 | 17191 | 2 |
| 1981 | 17203 | 12 |
| 1982 | 17207 | 4 |
| 1983 | 17209 | 2 |
| 1984 | 17231 | 22 |
Questions
What is the 1981st prime number?
17203.
Which prime number is 17203?
17203 is the 1981st prime number.
What is the sum of the first 1981 primes?
15,945,716.