What is the 1255th prime number?
The 1255th prime number is 10243. The next prime is 10247 (a gap of 4) and the one before is 10223.
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 1255th one is 10243.
- 2
10243 is prime because no prime up to ā10243 ā 101.21 divides it.
- 3
The primes are spread thinner as numbers grow: by the prime number theorem the 1255th prime is close to 1255 Ć ln(1255) ā 8954, and here it is 10243.
- 4
10243 has no twin: neither 10241 nor 10245 is prime.
Primes around the 1255th
| Position | Prime | Gap from the previous |
|---|---|---|
| 1252 | 10193 | 12 |
| 1253 | 10211 | 18 |
| 1254 | 10223 | 12 |
| 1255 | 10243 | 20 |
| 1256 | 10247 | 4 |
| 1257 | 10253 | 6 |
| 1258 | 10259 | 6 |
Questions
What is the 1255th prime number?
10243.
Which prime number is 10243?
10243 is the 1255th prime number.
What is the sum of the first 1255 primes?
5,999,544.