# Billion digit prime numbers?

In January this year a professor at the University of Central Missouri discovered the largest known prime number, and it’s a massive 17,425,170 digits long! It was discovered using software from the Great Internet Mersenne Prime Search, which uses thousands of networked computers to search for record-breaking prime numbers.

Prime numbers are numbers that can only be divided by themselves and one. Over 2000 years ago the Greek mathematician Euclid proved there is an infinite number of prime numbers; since then, mathematicians have tried to find larger and larger examples. The Electronic Frontier Foundation has promised a prize of $250,000 to the first individual or group to discover a prime number with at least 1,000,000,000 digits.