261728 · 5113848 - 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:261728 · 5113848 - 1
Verification status (*):Proven
Official Comment:
Proof-code(s): (*):p209 : Keppler, Srsieve, SierpinskiRiesel, PRP, OpenPFGW
Decimal Digits:79582   (log10 is 79581.754903834)
Rank (*):45914 (digit rank is 1)
Entrance Rank (*):4443
Currently on list? (*):no
Submitted:10/20/2006 15:47:24 CDT
Last modified:10/20/2006 16:31:36 CDT
Removed (*):2/3/2007 17:03:23 CDT
Database id:78691
Status Flags:none
Score (*):38.8504 (normalized score 0.0058)

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/TrialDiv/TrialDiv -q 261728 5 113848 -1 2>&1
[Elapsed time: 8.950 seconds]
modified2007-03-03 21:00:43
created2006-10-20 15:52:01

machineRedHat P4 P4
notesCommand: /home/caldwell/client/pfgw -tp -q"261728*5^113848-1" 2>&1
PFGW Version 20031027.x86_Dev (Beta 'caveat utilitor') [FFT v22.13 w/P4]
Primality testing 261728*5^113848-1 [N+1, Brillhart-Lehmer-Selfridge]
Running N+1 test using discriminant 3, base 1+sqrt(3)
Using SSE2 FFT
Adjusting authentication level by 1 for PRIMALITY PROOF
Reduced from FFT(32768,20) to FFT(32768,19)
Reduced from FFT(32768,19) to FFT(32768,18)
Reduced from FFT(32768,18) to FFT(32768,17)
528746 bit request FFT size=(32768,17)
Calling Brillhart-Lehmer-Selfridge with factored part 99.99%
261728*5^113848-1 is prime! (-2037.6773s+0.0100s)
[Elapsed time: 2315 seconds]
modified2007-03-03 21:00:43
created2006-10-20 15:53:01

Query times: 0.0005 seconds to select prime, 0.0006 seconds to seek comments.