Prime Number Checker
One entry per line - check primality, list primes in a range, or find the Nth prime
Mode:
Max results:
Separator:
Calculation Result
Download CSV
| No. | Value | Result | Detail |
|---|
Introduction to the tool and how to use it
Prime checker and generator: one input box handles three common needs, one entry per line, many lines at once.
Composite numbers show their smallest prime factor (for example 360 = 2 × 180), while primes are marked yes. Large integers use BigInt plus Miller-Rabin (deterministic below 2^64), so no floating-point error; range mode uses the Sieve of Eratosthenes and returns instantly up to 5 000 000.
Composite numbers show their smallest prime factor (for example 360 = 2 × 180), while primes are marked yes. Large integers use BigInt plus Miller-Rabin (deterministic below 2^64), so no floating-point error; range mode uses the Sieve of Eratosthenes and returns instantly up to 5 000 000.
How to use
- Choose a mode:
· Check primality: one integer per line, such as97;
· Generate a prime list: one range per line, such as100,200;
· Nth prime: one index per line, such as1000. - Click start calculation; the result table shows the verdict, prime count, or the Nth prime.
- Results can be copied with one click and exported as CSV.
Prime test
Primes between 100 and 200
Between 100 and 200 there are 21 primes, from 101 up to 199.
- Range100 ~ 200
- Divisors21
- Smallest prime in range101
- Largest prime in range199
Primes in range
| # | Prime |
|---|---|
| 1 | 101 |
| 2 | 103 |
| 3 | 107 |
| 4 | 109 |
| 5 | 113 |
| 6 | 127 |
| 7 | 131 |
| 8 | 137 |
| 9 | 139 |
| 10 | 149 |
| 11 | 151 |
| 12 | 157 |
| 13 | 163 |
| 14 | 167 |
| 15 | 173 |
| 16 | 179 |
| 17 | 181 |
| 18 | 191 |
| 19 | 193 |
| 20 | 197 |
| 21 | 199 |
- Large numbers are decided with Miller-Rabin (12 bases), which is deterministic below 2^64.
Common inputs
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