25 · 21211488 + 1

At this site we maintain a list of the 5000 Largest Known Primes which is updated hourly.  This list is the most important PrimePages database: 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:

Description:25 · 21211488 + 1
Verification status (*):Proven
Official Comment (*):Generalized Fermat, divides GF(1211487,12)
Proof-code(s): (*):g279 : Cooper, NewPGen, PRP, Proth.exe
Decimal Digits:364696   (log10 is 364695.62532697)
Rank (*):17546 (digit rank is 1)
Entrance Rank (*):46
Currently on list? (*):short
Submitted:1/21/2005 00:50:18 UTC
Last modified:3/11/2023 15:54:10 UTC
Database id:73208
Status Flags:none
Score (*):43.5356 (normalized score 0.2796)

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.
Generalized Fermat Divisors (bases 3,5,6,10,12) (archivable *)
Prime on list: yes, rank 20, weight 46.754497332787
Subcategory: "Divides GF(*,12)"
(archival tag id 187091, tag last modified 2023-03-31 01:37:05)
Generalized Fermat (archivable *)
Prime on list: no, rank 3862
Subcategory: "Generalized Fermat"
(archival tag id 204726, tag last modified 2023-10-04 16:37:20)

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.
machineLinux P4 2.8GHz
notesCommand: /home/caldwell/client/pfgw -f -t -q"25*2^1211488+1" 2>&1 PFGW Version 20031027.x86_Dev (Beta 'caveat utilitor') [FFT v22.13 w/P4] Primality testing 25*2^1211488+1 [N-1, Brillhart-Lehmer-Selfridge] trial factoring to 135290858 Running N-1 test using base 3 Using SSE2 FFT Adjusting authentication level by 1 for PRIMALITY PROOF Reduced from FFT(163840,20) to FFT(163840,19) Reduced from FFT(163840,19) to FFT(163840,18) Reduced from FFT(163840,18) to FFT(163840,17) Reduced from FFT(163840,17) to FFT(163840,16) 2422994 bit request FFT size=(163840,16) Calling Brillhart-Lehmer-Selfridge with factored part 100.00% 25*2^1211488+1 is prime! (-1567.4892s+0.0000s)
modified2020-07-07 22:30:44
created2005-01-21 00:53:01

Query times: 0.0002 seconds to select prime, 0.0002 seconds to seek comments.
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