Instantly check if any number is prime — and see its factors
Enter a Number
Whole numbers from 0 to 10¹⁵
Result
97 is divisible only by 1 and itself.
Quick Examples
A prime number checker lets you instantly verify whether any whole number is prime — divisible only by 1 and itself. Enter a number to get an immediate verdict, a full prime factorization with exponent notation, every individual prime factor, and the nearest primes on either side. Works for numbers up to one quadrillion right in your browser.
A prime number is a whole number greater than 1 that has no positive divisors other than 1 and itself. Examples include 2, 3, 5, 7, 11, and 13. The number 2 is the only even prime.
Prime factorization breaks a composite number down into the prime numbers that multiply together to produce it. For example, 60 = 2² × 3 × 5. Every integer greater than 1 has a unique prime factorization.
No. By modern definition, 1 is neither prime nor composite. Prime numbers must be greater than 1 and have exactly two distinct divisors: 1 and themselves.
The checker supports numbers up to 10¹⁵ (one quadrillion). It uses trial division optimized with a 6k ± 1 wheel, which is fast enough for instant results in the browser for all numbers in that range.