Posted on behalf of Amber Dance
What starts with 316, ends with 511, and has no factors besides itself and one?
The biggest prime number ever, that’s what.
Edson Smith of UCLA, in conjunction with the Great Internet Mersenne Prime Search (GIMPS) will share a $100,000 prize offered by the Electronics Frontier Foundation (EFF) for the first 10-million digit prime. One of the 75 computers Smith manages (Scientific American), running GIMPS’ free distributed computing software that utilizes processor downtime, discovered the number on 23 August, but it took three weeks to verify. It was a photo finish — Hans-Michael Elvenich of Langfelden, Germany, discovered another 10-million-digit prime just two weeks later. While Smith’s number clocked 12,978,189 digits, Elvenich’s was a puny 11,185,272 digits long.
Mersenne primes, which fit the equation 2^n -1, are the (relatively) easiest to prove prime because there’s a “simple” test for their primeness. The first four Mersennes, 3, 7, 31 and 127, were discovered BCE, and mathematicians have been adding to the list since the 15th Century. Computers speed up the process a bit—in its 12 years GIMPS has been running, it’s discovered a dozen Mersenne primes.
Smith’s number, with a record 12,978,189 digits, is 2^43,112,609 -1. Landon Curt Noll, who discovered his own pair of Mersenne primes as a high school student in the ‘70s, helpfully calculated how to say it (think: quattuormilliamilliatrecensexviginmilliaunsexagintillion).
Smith simply hoped the prime project would get undergraduates interested in math, but it will also bring the university US$50,000. GIMPS will get $5,000 for expenses, donate $25,000 to charities, and distribute the remainder to recent discoverers of lesser primes. EFF hopes the prize {https://www.eff.org/awards/coop} will encourage cooperative computing. Prime numbers are useful in math and cryptography, but distributed computing allows anyone with a PC to join in scientific research, from the hunt for ET to number crunching for the Large Hadron Collider (symmetry).
Want to get in on the action? EFF will bestow $150,000 on whoever breaks the 100-million-digit barrier. Download the free GIMPS software — you have a one in 2,000,000 chance of winning! And soon you’ll be able to get 2^43,112,609 -1 in poster form — a decoration sure to dazzle.