Tool to search for primes numbers according to criteria. A prime number is a natural number whose divisors are 1 and itself (like 2, 3, 5, 7, 11, 13, 17, 19 ...)

dCode is free and its tools are a valuable help in games, maths, geocaching, puzzles and problems to solve every day! A suggestion ? a feedback ? a bug ? an idea ? Write to dCode!

To know if a number is prime, it is necessary to pass primality test. A test that will verify mathematically and algorithmically, that the number is divisible by none other than itself.

Example:10 is divisible by 2 so is not prime

Example:11 is not divisible by 2, 3, 4, 5, 6, 7, 8, 9, or 10, so it's a prime.

There is no method (other than testing all numbers) to find a list of prime numbers exhaustively and quickly.

How do I find the next or previous prime number?

Again, it has no foolproof technique to detect the next prime or the previous prime, dCode will detect the first number (upper or lower) that will be a prime number.

Source code

dCode retains ownership of the online "Prime Numbers Search" source code. Except explicit open source licence (indicated CC / Creative Commons / free), the "Prime Numbers Search" algorithm, the applet or snippet (converter, solver, encryption / decryption, encoding / decoding, ciphering / deciphering, translator), or the "Prime Numbers Search" functions (calculate, convert, solve, decrypt / encrypt, decipher / cipher, decode / encode, translate) written in any informatic language (Python, Java, PHP, C#, Javascript, Matlab, etc.) and all data download, script, copy-paste, or API access for "Prime Numbers Search" are not public, same for offline use on PC, tablet, iPhone or Android ! Remainder : dCode is free to use.

Need Help ?

Please, check our dCode Discord community for help requests! NB: for encrypted messages, test our automatic cipher identifier!

Questions / Comments

Thanks to your feedback and relevant comments, dCode has developed the best 'Prime Numbers Search' tool, so feel free to write! Thank you!

Thanks to your feedback and relevant comments, dCode has developed the best 'Prime Numbers Search' tool, so feel free to write! Thank you!