In September 2006 the largest known prime number, a 9.8 million digit number, was discovered. If you find one over ten million digits you can win US$100,000 (of which you get to keep $50,000). No maths is required - just download the software and you're away. Warning: it takes about a month to run one primality check so some patience is required. Look out though Cooper and Boone look like they might beat you to it.
posted by meech on Apr 12, 2007 - 35 comments

You know about numbers, right? Natural numbers, rational numbers, integers, real numbers, complex numbers, prime numbers, funny numbers, illegal numbers. Illegal numbers? Well, there’s the illegal numbers game. Apparently 69 is illegal in Virginia, among other places. But did you know about illegal prime numbers? My brain is getting number by the day. (via digg)
posted by weapons-grade pandemonium on Apr 15, 2006 - 27 comments

26 year old student finds largest known prime number. The number is 6,320,430 digits long and would need 1,400 to 1,500 pages to write out. It is more than 2 million digits larger than the previous largest known prime number. Why? What use is it? How can knowing the next highest prime number be of any benefit?

One word: Cryptography.
Prime numbers are essential in producing keys for cryptography.
posted by DailyBread on Dec 10, 2003 - 14 comments

A Dell with a 2GHz Pentium processor owned by a Michigan State University student has found the world's largest prime number -- containing more than 6.3 million digits. The student was loaning his extra computer cycles to the GIMPS project [sort of like SETI and other monster farms]. Here's a web page he created about palindromic prime numbers before he became Mr. Biggest Prime Number Guy.
posted by jessamyn on Dec 2, 2003 - 27 comments

Find a 10 million digit prime number, get $100,000! "Now the bad news. Testing a single 10,000,000 digit number takes a full year on a 500 MHz Pentium III computer." This GIMPS organization merely provides software to do the searching process (not to mention they take most of the profits if you DO find a new prime).
posted by grank on May 18, 2001 - 3 comments

Mersenne Prime Search is a distributed computing project much like Seti@home, except instead of searching for aliens, you're in the running for $100,000 and a place in math history (shouldn't your computer actually be the one that goes into the math history books?).
posted by mathowie on Jul 7, 2000 - 1 comment