7917 · 2472407 + 1
(Another of the Prime Pages' resources)
The Largest Known Primes Icon
  View this page in:   language help
 
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:7917 · 2472407 + 1
Verification status (*):Proven
Official Comment:
Proof-code(s): (*):L1050 : Klausing, Srsieve, PrimeGrid, LLR
Decimal Digits:142213   (log10 is 142212.57572228)
Rank (*):34925 (digit rank is 1)
Entrance Rank (*):4282
Currently on list? (*):no
Submitted:10/7/2009 16:19:19 CDT
Last modified:10/7/2009 17:20:27 CDT
Removed (*):12/10/2009 11:10:19 CDT
Database id:90321
Status Flags:none
Score (*):40.6388 (normalized score 0.0337)

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_id90321
person_id9
machineDitto P4 P4
whattrial_divided
notesCommand: /home/ditto/client/TrialDiv/TrialDiv -q 7917 2 472407 1 2>&1
[Elapsed time: 9.932 seconds]
modified2011-12-27 16:48:42
created2009-10-07 16:35:11
id110017

fieldvalue
prime_id90321
person_id9
machineRedHat P4 P4
whatprime
notesCommand: /home/caldwell/client/pfgw -t -q"7917*2^472407+1" 2>&1
PFGW Version 20031027.x86_Dev (Beta 'caveat utilitor') [FFT v22.13 w/P4]
Primality testing 7917*2^472407+1 [N-1, Brillhart-Lehmer-Selfridge]
Running N-1 test using base 5
Using SSE2 FFT
Adjusting authentication level by 1 for PRIMALITY PROOF
Reduced from FFT(57344,20) to FFT(57344,19)
Reduced from FFT(57344,19) to FFT(57344,18)
Reduced from FFT(57344,18) to FFT(57344,17)
944848 bit request FFT size=(57344,17)
Calling Brillhart-Lehmer-Selfridge with factored part 100.00%
7917*2^472407+1 is prime! (1174.0400s+0.0000s)
[Elapsed time: 19.82 minutes]
modified2009-11-24 13:57:50
created2009-10-07 16:31:44
id110015

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