Prime Number Checker
Check if a number is prime.
If not, see its factors.
Also shows nearby prime numbers.
Prime Check Result
A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself.
First 30 prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113
Primality test method:
To check if n is prime, test divisibility by all integers from 2 up to the square root of n:
If no divisor found ≤ √n, then n is prime
Fun facts:
- 2 is the only even prime number
- There are infinitely many prime numbers (proved by Euclid ~300 BC)
- The largest known prime (as of 2024) has over 41 million digits
- Twin primes are pairs like (11, 13) that differ by 2