89595955370432 · 2371# - 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:89595955370432 · 2371# - 1
Verification status (*):Proven
Official Comment:Cunningham chain (32p+31)
Unofficial Comments:This prime has 1 user comment below.
Proof-code(s): (*):p364 : Batalov, NewPGen, OpenPFGW
Decimal Digits:1017   (log10 is 1016.7024710987)
Rank (*):112650 (digit rank is 5)
Entrance Rank (*):109118
Currently on list? (*):short
Submitted:3/24/2015 23:58:45 CDT
Last modified:3/25/2015 00:20:25 CDT
Database id:119628
Status Flags:TrialDiv
Score (*):25.3238 (normalized score 0)

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.
Cunningham Chains (1st kind) (archivable class *)
Prime on list: yes, rank 1, weight 52.0810942750392
Subcategory: "Cunningham chain (32p+31)"
(archival tag id 217960, tag last modified 2016-03-15 13:57:15)

User comments about this prime (disclaimer):

User comments are allowed to convey mathematical information about this number, how it was proven prime.... See our guidelines and restrictions.

Serge Batalov writes (31 Mar 2015): 
This is the first known titanic Cunningham Chain of length six.

Found as a subsequence of a (lot of) sieved candidate chains of length eight; starting testing from the middle, one gets three chances to win in this "lottery", yet the stream of candidates is not yet prohibitively thin.

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_id119628
person_id9
machineUsing: Xeon 4c+4c 3.5GHz
whatprime
notesCommand: /home/caldwell/client/pfgw/pfgw64 -tp -q"89595955370432*2371#-1" 2>&1
PFGW Version 3.7.7.64BIT.20130722.x86_Dev [GWNUM 27.11]
Primality testing 89595955370432*2371#-1 [N+1, Brillhart-Lehmer-Selfridge]
Running N+1 test using discriminant 2393, base 1+sqrt(2393)
Calling Brillhart-Lehmer-Selfridge with factored part 33.43%


89595955370432*2371#-1 is prime! (0.5709s+0.0004s)
[Elapsed time: 0.00 seconds]
modified2015-04-20 07:32:09
created2015-03-25 00:01:02
id165233

Query times: 0.0004 seconds to select prime, 0.0008 seconds to seek comments.