(2221509 - 1)/292391881

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:(2221509 - 1)/292391881
Verification status (*):PRP
Official Comment (*):Mersenne cofactor, ECPP
Unofficial Comments:This prime has 1 user comment below.
Proof-code(s): (*):E12 : Enge, Underwood, CM
Decimal Digits:66673   (log10 is 66672.387344224)
Rank (*):55750 (digit rank is 1)
Entrance Rank (*):54305
Currently on list? (*):short
Submitted:10/16/2023 19:21:28 UTC
Last modified:10/16/2023 19:37:13 UTC
Database id:136534
Status Flags:Verify
Score (*):38.3047 (normalized score 0.0012)

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.
Elliptic Curve Primality Proof (archivable *)
Prime on list: yes, rank 3
Subcategory: "ECPP"
(archival tag id 228876, tag last modified 2023-10-16 19:37:14)
Mersenne cofactor (archivable *)
Prime on list: yes, rank 1
Subcategory: "Mersenne cofactor"
(archival tag id 228877, tag last modified 2023-10-16 19:37:15)

User comments about this prime (disclaimer):

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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_id136534
person_id9
machineUsing: Digital Ocean Droplet
whatprp
notesCommand: /var/www/clientpool/1/pfgw64 -V -f -tc -q"(2^221509-1)/292391881" >command_output 2>&1
PFGW Version 4.0.4.64BIT.20221214.x86_Dev [GWNUM 30.11]
Primality testing (2^221509-1)/292391881 [N-1/N+1, Brillhart-Lehmer-Selfridge]
trial


Running N-1 test using base 3
Generic modular reduction using generic reduction AVX-512 FFT length 24K on A 221481-bit number
Running N+1 test using discriminant 11, base 1+sqrt(11)
Generic modular reduction using generic reduction AVX-512 FFT length 24K on A 221481-bit number
Calling N-1 BLS with factored part 0.02% and helper 0.01% (0.06% proof)


(2^221509-1)/292391881 is Fermat and Lucas PRP! (231.6302s+0.0008s)
[Elapsed time: 3.92 minutes]
modified2023-10-16 19:36:29
created2023-10-16 19:32:34
id182368

Query times: 0.0002 seconds to select prime, 0.0004 seconds to seek comments.
Printed from the PrimePages <t5k.org> © Reginald McLean.