What is The sieve of Eratosthenes?

The sieve of Eratosthenes

In mathematics, the sieve of Eratosthenes (Greek: κόσκινον Ἐρατοσθένους) is a simple, ancient algorithm for finding all prime numbers up to a specified integer. It works efficiently for the smaller primes (below 10 million). The sieve was described and attributed to Eratosthenes in the Introduction to Arithmetic by Nicomachus. More info


You can type any number up to 10,000,000,000 and it will show up to 10,000 consecutive numbers.

Color key:
Prime or 1 = Purple
Divisible by 2 = pink
Divisible by 3 = green
Divisible by 5 = blue
Divisible by 7 = yellow
Composite number = gray

Clicking any color will other than prime will turn any numbers with that factor gray.

Use in conjunction with Prime Number Check (Note: This is a gateway to the old website content)

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