# GIMPS
Finds a Prime!
*2*^{1398269}-1 is prime

^{1398269}-1 is prime

How do you slay a giant? One way is to get a very big gun. Most of the
previous record primeswere found just that way--by the super-computers of their day armed with
the Lucas-Lehmer
test.

Another way is to get together with several hundred friends and assault
the giant as a team. Recently the GIMPS(Great Internet Mersenne Prime Search) project did just that! On 13 November
1996 Joel
Armengauddiscovered the new Mersenne
prime2^{1398269}-1. He did this by *using* George
Woltman'sfree implementationof the Lucas-Lehmer
test*and by working together with* over 700
other individualsscattered across the Internet.

And what a giant they slew! This 420921 digit number (formed by multiplying
two by itself 1398268 times, then subtracting one) is now the largest
known prime. It is also the 35th
knownMersenne prime, and so comes paired with the 35th known perfect
number. There are still infinitely
manymore giants left to slay, so why not surf over to Woltman's
GIMPS siteand join the search for the next record prime?

For more information click on one of the following:

- About
**this prime** - The official press release
- Armengaud's announcement(11/23/96)
- Woltman's announcement(11/23/96)
- Articles: San Jose Mercury News (11/23/96)
- The complete decimal expansion
- About
**the GIMPS project** - Introduction(Home Page)
- Search Credits
- Search status(there is also a graphical view)
- June 96 San Jose Mercury News article
- About
**Mersenne primes** - Mersenne Primesdefinitions, theorems, lists...
- Marin Mersennereferences, images, sounds...
- Mersenne Primes Bibliography
- Mersenne mailing list
- About
**primes in general** - Lists of the Largest Known Primes
- How do you find primes and prove primality
- Home page for prime information