University of Central Missouri finds the largest known prime number

It could be a never-ending race, this Great Internet Mersenne Prime Search, known as GIMPS.

But as of Wednesday a professor at the University of Central Missouri in Warrensburg has the lead.

Curtis Cooper, a professor of computer science there, has made the most recent discovery of the world’s largest known prime number, it was announced Wednesday.

The new number, 2 multiplied by itself 57,885,161 times, minus 1, has 17,425,170 digits. Primes are numbers that can only be divided by themselves and 1, such as 2, 3, 5, 7 and 11.

The latest discovery was made by one of more than 1,000 computers running for 39 days across the campus in Warrensburg. The actual prime number was found by Computer 22, and the university is eligible for a $3,000 GIMPS research discovery award.

In the last seven years the University of Central Missouri has found the largest prime number in the world three times. Cooper and a colleague, Steven Boone, a professor of chemistry, announced their first discovery in 2005 and a second in 2006. The University of California, Los Angeles made the next discovery in 2008.

UCLA got kudos for having found the largest prime for four years until this latest announcement by the University of Central Missouri. It has been the longest period between prime discoveries since the launch of GIMPS, a computing project that has involved tens of thousands of machines since 1996.

Cooper, who was being inundated with telephone calls Wednesday from curious media and congratulatory colleagues, said the new prime number is in a special class of “extremely rare prime numbers known as Mersenne primes.” His is only the 48th known Mersenne prime ever discovered. The GIMPS project has found the last 14 Mersenne primes.

Cooper said that as the primes found get larger, it will take mathematicians longer to discover new ones.