Monster Prime Number Discovered by Scientists
May 18, 2011
EAGAN, Minn. -- Computer scientists crunching numbers at the outer limits of numeration say they've stumbled on the largest-known prime number. Primes are whole numbers, like 3, 5, 17, 23 and so on, that are evenly divisible only by one and themselves. This one, at 378,632 digits, would fill up 12 newspaper pages in standard type. Mathematicians would express the number as two to the 1,257,787th power minus one. A team from Cray Research, a unit of Silicon Graphics Inc. of Mountain View, Calif., discovered this latest, largest prime number while testing a Cray T94 system, one of the company's latest supercomputers, at Cray's engineering and manufacturing operation in Chippewa Falls, Wis. ``Finding these special numbers is a true `needle-in-a-haystack' exercise, but we improve our odds by using tremendously fast computers and a clever program,'' said Davina Benites, a Cray Research scientist. Mr. Benites and fellow researcher Paulene Arredondo developed the program, used as a quality-assurance test on supercomputer systems, that found the number.
