252191 · 25497878 - 1
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GIMPS has discovered a new largest known prime number: 282589933-1 (24,862,048 digits)

At this site we maintain a list of the 5000 Largest Known Primes which is updated hourly. This list is the most important databases at The Prime Pages: a collection of research, records and results all about prime numbers. This page summarizes our information about one of these primes.

This prime's information:

field (help)value
Description:252191 · 25497878 - 1
Verification status (*):Proven
Official Comment:
Unofficial Comments:This prime has 1 user comment below.
Proof-code(s): (*):L3183 : Haller, Srsieve, PrimeGrid, LLR
Decimal Digits:1655032   (log10 is 1655031.59223068)
Rank (*):123 (digit rank is 1)
Entrance Rank (*):21
Currently on list? (*):short
Submitted:6/23/2012 12:22:47 CDT
Last modified:6/24/2012 23:50:25 CDT
Database id:107886
Status Flags:none
Score (*):48.1783 (normalized score 57.3777)

User comments about this prime (disclaimer):

User comments are allowed to convey mathematical information about this number, how it was proven prime.... See our guidelines and restrictions.

PrimeGrid writes (11 Sep 2014): 
For more information, please see the Official Announcement.

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.
machineRedHat P4 P4
notesCommand: /home/caldwell/client/llr.pl 252191*2^5497878-1 2>&1
Starting Lucas Lehmer Riesel prime test of 252191*2^5497878-1
Using Zero Padded IBDWT : Mersenne fftlen = 327680, Used fftlen = 655360
V1 = 4 ; Computing U0...
V1 = 4 ; Computing U0...done.
Starting Lucas-Lehmer loop...

252191*2^5497878-1 is prime! Time : 126342.229 sec.
[Elapsed time: 35.10 hours]
modified2012-07-16 11:32:58
created2012-06-23 12:23:01

machineDitto P4 P4
notesCommand: /home/ditto/client/TrialDiv/TrialDiv -q 252191 2 5497878 -1 2>&1
[Elapsed time: 11.332 seconds]
modified2012-07-16 11:32:58
created2012-06-23 12:35:12

Query times: 0.0005 seconds to select prime, 0.0008 seconds to seek comments.