Factorize a positive integer, test primality, list all primes up to N (Sieve of Eratosthenes) and count them.
Result
Prime factorization
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Prime check
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Prime count π(N)
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Smallest prime factor
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All primes ≤ N
Enter a positive integer N (1 ≤ N ≤ 10,000,000). The tool then: (a) shows the prime factorization, e.g. 60 = 2² × 3 × 5; (b) tests whether N itself is prime; (c) lists every prime up to N using the Sieve of Eratosthenes; (d) gives π(N), the count of primes ≤ N. Everything runs locally in your browser via a sieve — nothing is uploaded.