2^42643801 - 1

This prime's information:

Archival tags:

There are certain forms classed as archivable: these prime may (at times) remain on this list even if they do not make the Top 5000 proper.  Such primes are tracked with archival tags.

Mersenne (archivable *)

Prime on list: yes, rank 7
Subcategory: "Mersenne"
(archival tag id 210459, tag last modified 2024-10-21 21:37:25)

User comments about this prime (disclaimer):

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Great Internet Mersenne Prime Search by Woltman & Kurowski writes (11 Sep 2014):  (report abuse)

On April 12th, the 47th known Mersenne prime, 242,643,801-1, 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 independently verified 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 EX CPUs. 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!

Chris Caldwell writes (22 Feb 2018):  (report abuse)

Every Mersenne number less than this one has been checked once for primality by GIMPS (by September 5, 2012), but not twice. As of February 22, 2018, all tests below M(42 643 801) are verified by GIMPS, officially making it the 46th Mersenne prime

Verification data:

The Top 5000 Primes is a list for proven primes only. In order to maintain the integrity of this list, we seek to verify the primality of all submissions.  We are currently unable to check all proofs (ECPP, KP, ...), but we will at least trial divide and PRP check every entry before it is included in the list.