About www.numere-prime.ro website

What is numere-prime.ro?

numere-prime.ro is a website that provides you with the online capability of:

  • running automatically prime factorization on composite numbers (decompose, break down numbers into prime factors)
  • determining whether a number is prime or not
  • calculating the greatest common factor GCF (also called the greatest common divisor GCD, or the highest common factor HCF) of two numbers
  • calculating the least common multiple LCM of two numbers
  • reducing math ordinary fractions to lower terms (fractions simplification)
  • checking if a number is divisible by another
  • calculating all the divisors of a number or all the common divisors of two numbers
  • determining whether two numbers are coprime (prime to each other)
  • checking on numbers' parity (even or odd)

What is the main purpose of numere-prime.ro

numere-prime.ro aims to provide users a free reliable collection of tools that automatically perform operations related to prime factors or numbers' parity. This tool can be used both as a tool to perform the above operations fast, in order to save time, but also as an online checking tool for those knowing how to do those operations by themselves.

Why this website?

In 2012 I wrote a short article about prime numbers in the section of "known facts" of haios.ro website. This short article contained a list of prime numbers up to 200. I noticed that the site visitors were very interested in this short article.

Here's a link to this article, containing a list of prime numbers up to 200, in the section of haios.ro curiosities (Romanian language): list of prime numbers up to 200. From here to the idea of creating a website that automatically performs the prime factorization algorithm in order to determine whether a number is prime or not, it was not a long way: numbere-prime.ro.

What can you do?

If you find this website useful, spread the word, tell your friends, colleagues and those that need a prime factorization tool. At the same time, any feedback to improve our service is more than welcomed and ultimately helps all the visitors.


We thank all our visitors that recommend friends and colleagues numere-prime.ro website or come by with valuable suggestions. Our site will continue to grow and develop thanks to you and your opinions. :-)

numere-prime.ro team

email / contact: email numere-prime.ro