81 561 761 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 =	695000
B2 =	14247500

Status	Date	User	Residue	Shift	Software
Verified	2017-10-23	mathprofrockstar	2D64DD3F7BF7F0DF	75293436	Windows 64-bit,Prime95,v26.6,build 3
Verified	2026-04-03	Lacni	2D64DD3F7BF7F0DF	50025454	Windows 64-bit,Prime95,v30.19,build 13

History

Date	User	Type	Result
2026-04-03	Lacni	C-LL	2D64DD3F7BF7F0DF
2025-10-08	Sid & Andy	NF	no factor TF: 75-76
2017-10-23	mathprofrockstar	C-LL	2D64DD3F7BF7F0DF
2017-05-22	TheJudger	NF-PM1	B1=695000, B2=14247500, E=12
2016-10-14	-anonymous-	NF	no factor TF: 74-75
2016-10-14	-anonymous-	NF	no factor TF: 73-74
2016-10-14	-anonymous-	NF	no factor TF: 72-73
2016-10-14	-anonymous-	NF	no factor TF: 71-72
2015-06-30	monst	NF	no factor TF: 70-71
2014-02-03	Thomas Kerscher	NF	no factor TF: 69-70
2014-02-02	Thomas Kerscher	NF	no factor TF: 68-69
2014-02-01	Thomas Kerscher	NF	no factor TF: 67-68
2013-01-30	phoenicis	NF	no factor TF: 66-67
2012-08-09	Carsten Kossendey	NF	no factor TF: 65-66
2010-12-15	Architects Cubed	NF	no factor TF: 64-65