Prime Number Checker
Check whether a number is prime, and see its prime factors if it isn't.
97 is a prime number.
Processing happens locally in your browser. Nothing you enter is uploaded.
How It Works
Enter a whole number to check whether it's prime. Non-prime numbers show their prime factorization.
A prime number has exactly two divisors: 1 and itself
Example
97 is prime. 12 is not prime — it factors into 2 × 2 × 3.
Frequently Asked Questions
- Is 1 a prime number?
- No — by definition, a prime number has exactly two distinct divisors (1 and itself), but 1 has only one divisor, so it's neither prime nor composite.
- Is 2 the only even prime number?
- Yes — every other even number is divisible by 2, so it can't have exactly two divisors.
Related Tools
GCD Calculator
Editor's pickFind the greatest common divisor of two numbers.
LCM Calculator
Editor's pickFind the least common multiple of two numbers.
Average Calculator
Similar toolFind the mean, median, min, and max of a list of numbers.
Cube Root Calculator
Similar toolFind the cube root of any number, including negatives.
Fraction Calculator
Similar toolAdd, subtract, multiply, or divide two fractions and simplify the result.
Ratio Calculator
Similar toolSimplify a ratio, or solve for a missing value in a proportion.