Prime Number Checker
Verify instantly whether a number is prime or composite
Prime Number Checker
Check if a number is prime and find prime numbers in range
Find Primes in Range
Special Prime Numbers
2
Smallest and only even prime
3
Smallest odd prime
17
Fermat prime
31
Mersenne prime (2⁵-1)
997
Largest 3-digit prime
7919
1000th prime
About Prime Numbers
A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. Prime numbers are the building blocks of all natural numbers.
Twin Primes
Twin primes differ by 2 (e.g., 11 & 13)
Mersenne Primes
Mersenne primes: 2^p - 1 where p is prime
Fermat Primes
Fermat primes: 2^(2^n) + 1
Palindromic Primes
Palindromic primes read same forward/backward
Emirp Primes
Emirp primes: remain prime when reversed
Frequently Asked Questions (FAQs)
A prime number is a natural number greater than 1 that has no divisors other than 1 and itself. Example: 2, 3, 5, 7, 11.
The smallest prime number is 2. It is also the only even prime number.
To check if a number is prime, test if it is divisible by any integer from 2 up to its square root.
Prime numbers are used in cryptography, computer security, hashing algorithms, and mathematics.
No. By definition, prime numbers must be greater than 1.
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