81 485 293 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	2017-09-12	curtisc	7CCEC6A5BB005113	21669309	Windows Service,Prime95,v28.7,build 1
Verified	2026-02-08	Massimo Cappelli (ik5pwa)	7CCEC6A5BB005113	67086758	Linux 64-bit,Prime95,v30.19,build 20

History

Date	User	Type	Result
2026-02-08	Massimo Cappelli (ik5pwa)	C-LL	7CCEC6A5BB005113
2020-06-05	-anonymous-	NF	no factor TF: 75-76
2017-09-12	curtisc	C-LL	7CCEC6A5BB005113
2016-10-09	TheJudger	NF-PM1	B1=695000, B2=14247500, E=12
2016-09-20	AirSquirrels	NF	no factor TF: 74-75
2016-09-20	AirSquirrels	NF	no factor TF: 73-74
2016-09-20	AirSquirrels	NF	no factor TF: 72-73
2016-09-20	AirSquirrels	NF	no factor TF: 71-72
2015-02-21	el grocco	NF	no factor TF: 70-71
2013-06-14	Houd Al-Obaidli	NF	no factor TF: 69-70
2013-06-11	Houd Al-Obaidli	NF	no factor TF: 68-69
2013-02-16	Risto A. Paju	NF	no factor TF: 67-68
2013-01-30	phoenicis	NF	no factor TF: 66-67
2012-09-05	Carsten Kossendey	NF	no factor TF: 65-66
2010-12-15	Architects Cubed	NF	no factor TF: 64-65