Prime Number Checker

Instantly check if a number is prime and see its prime factorization. List all primes in a range. Free online prime number checker.

Frequently Asked Questions

What is a prime number?
A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. Examples include 2, 3, 5, 7, 11, and 13.
Is 1 a prime number?
No, 1 is not a prime number. By definition, a prime must be greater than 1 and divisible only by 1 and itself.
Can the checker handle very large numbers?
Yes, efficient algorithms are used to determine primality even for very large numbers. The prime factorization is also provided.
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