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
Is 1024 a prime number?
1024 is not a prime number. Its smallest prime factor is 2 and it factors as 2^10.
- Prime?No
- Smallest prime factor2
- Prime factorization2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2
- Divisors11
- Previous prime1021
- Next prime1031
Divisor list
| # | Divisor |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 16 |
| 6 | 32 |
| 7 | 64 |
| 8 | 128 |
| 9 | 256 |
| 10 | 512 |
| 11 | 1024 |
- Large numbers are decided with Miller-Rabin (12 bases), which is deterministic below 2^64.
Common inputs
Message board
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