21480! - 1
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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:21480! - 1
Verification status (*):Proven
Official Comment:Factorial
Proof-code(s): (*):p65 : DavisK, Kuosa, OpenPFGW
Decimal Digits:83727   (log10 is 83726.0159080268)
Rank (*):38949 (digit rank is 1)
Entrance Rank (*):124
Currently on list? (*):short
Submitted:9/3/2001 03:01:24 CDT
Last modified:9/3/2001 03:01:24 CDT
Database id:254
Status Flags:none
Score (*):39.0069 (normalized score 0.0115)

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.
Factorial primes (archivable *)
Prime on list: yes, rank 8
Subcategory: "Factorial"
(archival tag id 188528, tag last modified 2013-09-04 05:50:30)

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_id254
person_id9
machineWinXP P4 1.8GHz
whatprime
notesPrimality testing 21480!-1 [N+1, Brillhart-Lehmer-Selfridge] Calling Brillhart-Lehmer-Selfridge with factored part 33.69% 21480!-1 is prime! (14903.664000 seconds) PFGW Version 20021217.Win_Dev (Beta 'caveat utilitor') [FFT v22.7 w/P4] Running N+1 test using discriminant 21487, base 1+sqrt(21487)
modified2003-03-25 11:22:38
created2003-01-10 03:14:56
id65066

Query times: 0.0004 seconds to select prime, 0.0005 seconds to seek comments.