🔢 Prime Number Checker
Check if a number is prime and generate prime numbers up to any limit.
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Primes Found
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Largest Prime
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Sum of Primes
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Prime Number Checker
Check if any number is prime and generate all prime numbers up to a given limit using the Sieve of Eratosthenes. Shows factors for composite numbers.
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.
How large can the numbers be?
The checker works well for numbers up to about 10^15. Beyond that, JavaScript floating-point precision becomes a limitation.
How does the sieve work?
The Sieve of Eratosthenes efficiently finds all primes up to a given limit by iteratively marking composites.