19911001 · 2404076 + 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.

Description:19911001 · 2404076 + 1
Verification status (*):Proven
Official Comment (*):[none]
Proof-code(s): (*):g369 : Tamai, Proth.exe
Decimal Digits:121647   (log10 is 121646.29562101)
Rank (*):40508 (digit rank is 1)
Entrance Rank (*):378
Currently on list? (*):no
Submitted:1/2/2005 13:23:07 CDT
Last modified:1/2/2005 13:23:07 CDT
Removed (*):5/21/2009 08:35:00 CDT
Database id:72969
Status Flags:none
Score (*):40.1578 (normalized score 0.0135)

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"19911001*2^404076+1" 2>&1 PFGW Version 20031027.x86_Dev (Beta 'caveat utilitor') [FFT v22.13 w/P4] Primality testing 19911001*2^404076+1 [N-1, Brillhart-Lehmer-Selfridge] trial factoring to 42021281 Running N-1 test using base 3 Using SSE2 FFT Adjusting authentication level by 1 for PRIMALITY PROOF Reduced from FFT(49152,20) to FFT(49152,19) Reduced from FFT(49152,19) to FFT(49152,18) Reduced from FFT(49152,18) to FFT(49152,17) 808210 bit request FFT size=(49152,17) Calling Brillhart-Lehmer-Selfridge with factored part 99.99% 19911001*2^404076+1 is prime! (2412.7803s+0.0203s)
modified2020-07-07 17:30:45
created2005-01-02 13:53:00

Query times: 0.0002 seconds to select prime, 0.0003 seconds to seek comments.
Printed from the PrimePages <primes.utm.edu> © Chris Caldwell.