Curtis Cooper, professor of computer science at the University of Central Missouri, has made the most recent discovery of the world’s largest known prime number, according to information released by the Great Internet Mersenne Prime Number Search, also known as GIMPS.

The new number, 2 multiplied by itself 57,885, 161 times, minus 1, has 17,425,170 digits. The discovery was made by one of the more than 1,000 computers running for 39 days across the UCM campus. The actual prime number was found by Computer #22 in a computer lab in Wood 210 on the UCM campus at 11:30 p.m. Jan. 25. Following an extensive verification process completed by GIMPS, the newest known prime number was announced Feb. 5. The discovery is eligible for a $3,000 GIMPS research discovery award.

This is the third discovery for Cooper and UCM in the ongoing search for the largest prime number. Cooper and UCM colleague Steven Boone, professor of chemistry, announced their first discovery in 2005, followed by a second in 2006. The University of California-Los Angeles made the next discovery in 2008, followed by UCM’s most recent discovery.

“There are a lot of people on campus to thank,” Curtis said. “I’ve had great support from my department and my department chair, Xiadong Yue, and Dean Alice Greife of the College of Health, Science, and Technology, as well as the technical support from Technology Services and technology coordinators from departments and colleges across the campus. That support is what allowed us to use more than 1,000 computers to make the discovery possible.”

The new prime number is in a special class of extremely rare prime numbers known as Mersenne primes. It is only the 48th known Mersenne prime ever discovered, with each discovery become more difficult to find than the previous one. GIMPS has discovered the last 14 Meresenne primes.

GIMPS was formed in 1996 by George Woltman to discover the new world-record size Mersenne prime numbers. In 1997 Scott Kurowski enabled GIMPS to harness the power of hundreds of thousands of ordinary computers to complete the extraordinary search. Woltman developed the software that allows the massive network of computers to make the search and automatically report findings to GIMPS.

“When we first started working with the project in 1997, we had four computers on campus that we had to monitor individually, and we had to report our findings to GIMPS by email,” Cooper said. “Current technology allows us to undertake the search, and because the numbers are becoming larger with each discovery, it is anticipated that future discoveries will take longer.”

Learn more about the GIMPS and the world’s largest prime number search at

Press Release Courtesy of University of Central Missouri Public Affairs