What is the 55th prime number?
The 55th prime number is 257. The next prime is 263 (a gap of 6) and the one before is 251.
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 55th one is 257.
- 2
257 is prime because no prime up to ā257 ā 16.03 divides it.
- 3
The primes are spread thinner as numbers grow: by the prime number theorem the 55th prime is close to 55 Ć ln(55) ā 220, and here it is 257.
- 4
257 has no twin: neither 255 nor 259 is prime.
Primes around the 55th
| Position | Prime | Gap from the previous |
|---|---|---|
| 52 | 239 | 6 |
| 53 | 241 | 2 |
| 54 | 251 | 10 |
| 55 | 257 | 6 |
| 56 | 263 | 6 |
| 57 | 269 | 6 |
| 58 | 271 | 2 |
Questions
What is the 55th prime number?
257.
Which prime number is 257?
257 is the 55th prime number.
What is the sum of the first 55 primes?
6,338.