Computing project finds largest known prime number

Saved to a text file, it's 22.6 megabytes. Written out five digits per second, it would take 54 days to write. If sized at five digits per inch, it would cover 73 miles.

The largest known prime number, discovered Dec. 26 and known as M77232917, runs to 23,249,425 digits and is calculated by multiplying 2 by itself 77,232,917 times and then subtracting 1, a process known as a Mersenne Prime.

A distributed computing project, the Great Internet Mersenne Prime Search (GIMPS), discovered the number.

Volunteer Jonathan Pace's computer is credited with the discovery. Pace, 51, of Germantown, Tenn., is an electrical engineer who has participated as a GIMPS volunteer for more than 14 years.

Distributed computing projects allow people to volunteer their computers' down time to help run massive calculations for math and science projects. Volunteers download software that connects with the project's main computers, downloads packets of data, and analyzes and sends back the results.

As this post from FiveThirtyEight notes, similar projects are searching for signs of intelligent life in the universe and researching diseases.

Brian Bowling is a Tribune-Review staff writer. Reach him at 724-850-1218, bbowling@tribweb.com or via Twitter @TribBrian.