26780 · 19726780 - 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:26780 · 19726780 - 1
Verification status (*):Proven
Official Comment (*):Generalized Woodall
Proof-code(s): (*):p120 : Minovic, MultiSieve, GenWoodall, OpenPFGW
Decimal Digits:61451   (log10 is 61450.23334718)
Rank (*):56791 (digit rank is 1)
Entrance Rank (*):2267
Currently on list? (*):no
Submitted:11/22/2004 14:54:28 UTC
Last modified:3/11/2023 15:54:10 UTC
Database id:72458
Status Flags:none
Score (*):38.0532 (normalized score 0.0009)

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 Woodall (archivable *)
Prime on list: no, rank 117
Subcategory: "Generalized Woodall"
(archival tag id 188905, tag last modified 2024-02-26 15:37:18)

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.
fieldvalue
prime_id72458
person_id9
machineLinux P4 2.8GHz
whatprime
notesCommand: /home/caldwell/client/pfgw -f -tp -q"26780*197^26780-1" 2>&1 PFGW Version 20031027.x86_Dev (Beta 'caveat utilitor') [FFT v22.13 w/P4] Primality testing 26780*197^26780-1 [N+1, Brillhart-Lehmer-Selfridge] trial factoring to 20251449 Running N+1 test using discriminant 3, base 13+sqrt(3) Using SSE2 FFT Adjusting authentication level by 1 for PRIMALITY PROOF Reduced from FFT(24576,20) to FFT(24576,19) Reduced from FFT(24576,19) to FFT(24576,18) Reduced from FFT(24576,18) to FFT(24576,17) 408284 bit request FFT size=(24576,17) Calling Brillhart-Lehmer-Selfridge with factored part 99.99% 26780*197^26780-1 is prime! (3339.0901s+0.0092s)
modified2020-07-07 22:30:45
created2004-11-22 15:23:00
id77456

Query times: 0.0002 seconds to select prime, 0.0004 seconds to seek comments.
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