271357 · 28943013 - 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.

This prime's information:

Description:271357 · 28943013 - 1
Verification status (*):Proven
Official Comment (*):[none]
Unofficial Comments:This prime has 1 user comment below.
Proof-code(s): (*):A33 : Przystawik, Srsieve, CRUS, PRST
Decimal Digits:2692121   (log10 is 2692120.598154)
Rank (*):214 (digit rank is 1)
Entrance Rank (*):208
Currently on list? (*):yes
Submitted:10/13/2025 08:15:00 UTC
Last modified:10/18/2025 21:37:09 UTC
Database id:141148
Status Flags:none
Score (*):49.6694 (normalized score 52.1762)

User comments about this prime (disclaimer):

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Jeppe Stig Nielsen writes (13 Oct 2025):  (report abuse)

The n for which 271357*2^n - 1 is prime, are n = 1, 8943013, ..., so this prime is second in this sequence. But the first one (n = 1) does not satisfy 2^n > 271357.

In other words, the first prime of form 542714*2^m - 1 with m > 0.

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_id141148
person_id9
machineUsing: Digital Ocean Droplet
whatprime
notesCommand: /var/www/clientpool/1/pfgw64 -V -f -tp -q"271357*2^8943013-1" >command_output 2>&1
PFGW Version 4.0.4.64BIT.20221214.x86_Dev [GWNUM 30.11]
Primality testing 271357*2^8943013-1 [N+1, Brillhart-Lehmer-Selfridge]
trial
Running N+1 test using discriminant 3, base 1+sqrt(3)
Special modular reduction using FMA3 FFT length 864K, Pass1=384, Pass2=2304, clm=2 on 271357*2^8943013-1
Detected in MAXERR>0.45 (round off check) in Exponentiator::Iterate
Iteration: 52/8943033 ERROR: ROUND OFF 0.5>0.45
(Test aborted, try again using the -a1 switch)
Running N+1 test using discriminant 3, base 1+sqrt(3)
Special modular reduction using FMA3 FFT length 896K, Pass1=448, Pass2=2K, clm=2 on 271357*2^8943013-1
Calling Brillhart-Lehmer-Selfridge with factored part 100.00%


271357*2^8943013-1 is prime! (267604.6611s+0.0040s)
[Elapsed time: 3.10 days]
modified2025-10-18 21:33:45
created2025-10-15 19:13:40
id187238

Query times: 0.0003 seconds to select prime, 0.0004 seconds to seek comments.
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