On April 12th, the 47th known Mersenne prime, 2^42,643,801-1, a 12,837,064 digit number was found by Odd Magnar Strindmo from Melhus, Norway! This prime is the second largest known prime number, a "mere" 141,125 digits smaller than the Mersenne prime found last August.

Odd is an IT professional whose computers have been working with GIMPS since 1996 testing over 1400 candidates. This calculation took 29 days on a 3.0 GHz Intel Core2 processor.

The prime was first verified on June 12th by Tony Reix of Bull SAS in Grenoble, France using the Glucas program running on Bull NovaScale HPC servers, one featuring Itanium2 CPUs and another featuring Nehalem CPUs. The prime was later independently verified by Rob Giltrap of Sun Microsystems using Ernst Mayer's Mlucas program running on a Sun SPARC Enterprise M9000 Server.

Perfectly Scientific, Dr. Crandall's company which developed the FFT algorithm used by GIMPS, makes souvenir posters you can order. You'll need a good magnifying glass to read all 12.8 million digits!

On August 23rd, a UCLA computer in the GIMPS PrimeNet network discovered the 45th known Mersenne prime, 2^43,112,609-1, a mammoth 12,978,189 digit number! The prime number qualifies for the Electronic Frontier Foundation's $100,000 award for discovery of the first 10 million digit prime number. Congratulations to Edson Smith, who was responsible for installing and maintaining the GIMPS software on the UCLA Mathematics Department's computers.

On September 6th, the 46th known Mersenne prime, 2^37,156,667-1, a 11,185,272 digit number was found by Hans-Michael Elvenich in Langenfeld near Cologne, Germany! This was the first Mersenne prime to be discovered out of order since Colquitt and Welsh discovered 2^110,503-1 in 1988.

The nearly decade long quest for the EFF award came down to a close race to the finish - with just two weeks separating the discovery of the two primes.

As promised, GIMPS will give $50,000 of the EFF award to the UCLA Mathematics Department for discovering the first 10 million digit prime. $25,000 will go to charity, and most of the remainder will go to discoverers of the previous six Mersenne primes.

In recognition of the individual discoverers, the GIMPS project leaders, and every GIMPS participant's contributions, credit for the two primes goes to "Edson Smith, George Woltman, Scott Kurowski, et al.", and "Hans-Michael Elvenich, George Woltman, Scott Kurowski, et al.".

Edson Smith has worked in the IT industry for 27 years and the last 10 years as the Computing Manager for the UCLA Mathematics Department. Last Fall he replaced the Lab's screen savers with prime95 - a perfect fit for the Mathematics Department. UCLA has a rich history in the discovery of Mersenne primes. Dr. Raphael Robinson found five Mersenne primes at UCLA in 1952 and Alex Hurwitz found two more in 1961.

Hans-Michael Elvenich is a 44 year old Electrical Engineer working for Lanxess, a chemical company. He is a prime number enthusiast and is the owner and operator of www.primzahlen.de. In German, prime numbers are called "Primzahlen".

Both primes were first verified by Tom Duell (Burlington, MA, USA) and Rob Giltrap (Wellington, New Zealand), both of Sun Microsystems, using the Mlucas program by Ernst Mayer of Cupertino California USA. The verifications ran on 8 dual-core SPARC64 VI 2.15Ghz CPUs of a Sun SPARC Enterprise M5000 Server and 4 quad-core SPARC64 VII 2.52GHz CPUs of a Sun SPARC Enterprise M8000 Server in Menlo Park, CA, USA. The first prime verification took 13 days, the second prime took 5 days.

Both primes were also independently verified by Tony Reix of Bull SAS in Grenoble, France using 16 1.6 GHz Itanium2 CPUs of a Bull NovaScale 6160 HPC server and the Glucas program. Jeff Gilchrist of Carleton University in Ottawa, Canada has also verified both primes using up to 16 1.6 GHz Itanium2 CPUs of a server at SHARCNET, running the Glucas program by Guillermo Ballester Valor of Granada, Spain.

Perfectly Scientific, Dr. Crandall's company which developed the FFT algorithm used by GIMPS, will make posters you can order containing all 12.9 and 11.1 million digits. You'll need a good magnifying glass to read the tiny, tiny print!

You can read a little more in the short press release.

Mersenne Wiki Created. From the good folks that brought you the Mersenne Forums comes the Mersenne Wiki. Browse the Wiki to learn more about GIMPS and Mersenne Primes.

GIMPS forums. Here you can chat with fellow GIMPS members, get help with installation questions, learn more about how GIMPS works, etc.

You could discover one of the most coveted finds in all of Mathematics - a new Mersenne prime number. We've found twelve already. Join in on this fun, yet serious research project. All you need is a personal computer, patience, and a lot of luck.

In addition to the joy of making a mathematical discovery, you could win a (USD) $3,000 cash GIMPS Research Discovery Award for each Mersenne prime discovered, and the Electronic Frontier Foundation is offering a $150,000 award to the first person or group to discover a 100 million digit prime number! See how GIMPS will distribute this award if we are lucky enough to find the winning 100 million digit prime.

Prime numbers have long fascinated amateur and professional mathematicians. An integer greater than one is called a prime number if its only divisors are one and itself. The first prime numbers are 2, 3, 5, 7, 11, etc. For example, the number 10 is not prime because it is divisible by 2 and 5. A Mersenne prime is a prime of the form 2^P-1. The first Mersenne primes are 3, 7, 31, 127 (corresponding to P = 2, 3, 5, 7). There are only 46 known Mersenne primes.

GIMPS, the Great Internet Mersenne Prime Search, was formed in January 1996 to discover new world-record-size Mersenne primes. GIMPS harnesses the power of thousands of small computers like yours to search for these "needles in a haystack".

Most GIMPS members join the search for the thrill of possibly discovering a record-setting, rare, and historic new Mersenne prime. Of course, there are many other reasons.

Last Updated February 23, 2011