81 578 923 Exponent Status

Great Internet Mersenne Prime Search
GIMPS
Finding World Record Primes Since 1996

PrimeNet Exponent Status

M_n

Details

Composite: proven not-prime with Lucas-Lehmer test

No factors below 2⁷⁶

TF target 2⁷⁵

P-1

B1 =	730000
B2 =	14600000

Status	Date	User	Residue	Shift	Software
Verified	2017-09-24	curtisc	EA9878C3FEB4580C	61707549	Windows Service,Prime95,v28.7,build 1
Verified	2026-04-12	Mark Filipski	EA9878C3FEB4580C	57886391	Windows 64-bit,Prime95,v30.19,build 20

History

Date	User	Type	Result
2026-04-12	Mark Filipski	C-LL	EA9878C3FEB4580C
2025-10-20	Sid & Andy	NF	no factor TF: 75-76
2017-09-24	curtisc	C-LL	EA9878C3FEB4580C
2017-05-13	Architects Cubed	NF-PM1	B1=730000, B2=14600000, E=6
2016-11-06	TheJudger	NF	no factor TF: 74-75
2016-11-06	TheJudger	NF	no factor TF: 73-74
2016-10-09	Son Johan	NF	no factor TF: 72-73
2013-02-02	Davin	NF	no factor TF: 71-72
2013-02-02	Davin	NF	no factor TF: 69-70
2013-02-02	Davin	NF	no factor TF: 70-71
2013-02-02	Davin	NF	no factor TF: 68-69
2013-02-02	Davin	NF	no factor TF: 67-68
2013-01-30	phoenicis	NF	no factor TF: 66-67
2012-09-11	Carsten Kossendey	NF	no factor TF: 65-66
2010-12-10	Architects Cubed	NF	no factor TF: 64-65