Missouri professors discover largest prime number

With the help of 700 programmed computers, a team of researchers at Central Missouri State University (CMSU) identified the largest known prime number on December 15, 2005.

The 9.1 million-digit number, known as M30402457 or 2 to the 30,402,457th power minus 1, is the 43rd discovery in a special class of rare prime numbers known as Mersenne primes, named for the French monk Marin Mersenne, who studied these numbers more than 300 years ago. A prime number is a positive integer that can only be evenly divided by itself and the number 1.

Dr. Curtis Cooper, professor of computer science and mathematics, and Dr. Steven Boone, professor of chemistry and associate dean of the College of Arts and Sciences, led the research. They collaborated several years ago in the Great Internet Mersenne Prime Search (GIMPS) and used 700 campus computers as part of an international grid of 70,000 networked computers in every time zone of the world. The December 15th discovery was made using GIMPS software that ran on and off for about 50 days.

Cooper and Boone are the closest team in the running to receive a $100,000 prize from Electronic Frontier Foundation for the search of a 10 million-digit prime number.