1 717 981 Exponent Status

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

PrimeNet Exponent Status

M_n

Status

Details

Composite, with 2 known prime factors. Cofactor is composite.

Factored

Factor	Digits	Bits	Date
188686661849049690737	21	67.4	2014-02-07 15:20:42
2662295611013024504873	22	71.2	2020-06-08 08:21:28

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	107 / 640

Estimated T-Level: 25.8 ⓘ

TF below 2^81 is very unlikely to find new factors due to ECM effort.

Status	Date	User	Residue	Shift
Verified (Factored)		Dirk Swanson	F557CCC7A1D8A441	0
Verified (Factored)	1998-11-28	Nikolay Tehov	F557CCC7A1D8A441	877583

Status	Date	User	Residue	Shift	Type	Base
Verified (Factored)	2025-09-02	Kriesel	04320D0D371DC8DF	0	1	3

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified (Factored)	2017-09-30	alpertron	265C24741560061C	1	0	1	3
Verified (Factored)	2017-10-19	Oliver Kruse	265C24741560061C	1	258515	1	3
Verified	2020-06-09	M Miller	04320D0D371DC8DF	2	1472093	5	3
Verified	2020-06-11	arnaud	04320D0D371DC8DF	2	143883	5	3

History

Date	User	Type	Result
2025-09-03	Carlos Pinho	CERT	PRP Certification CERT proof power = 6 Proof certified good
2025-09-02	Kriesel	C-PRP	04320D0D371DC8DF PRP proof power = 6 PRP: Verified (Factored) Proof certified good
2020-06-11	arnaud	C-PRP	M1717981/188686661849049690737/2662295611013024504873 : 04320D0D371DC8DF PRP: Verified PRP without proof (not generated)
2020-06-09	M Miller	C-PRP	M1717981/188686661849049690737/2662295611013024504873 : 04320D0D371DC8DF PRP: Verified PRP without proof (not generated)
2020-06-08	TJAOI	F-ECM	Factor: 2662295611013024504873 / (ECM curve 30, B1=50000, B2=5000000)
2017-10-19	Oliver Kruse	C-PRP	M1717981/188686661849049690737 : 265C24741560061C PRP: Verified PRP without proof (not generated)
2017-09-30	alpertron	C-PRP	M1717981/188686661849049690737 : 265C24741560061C PRP: Verified PRP without proof (not generated)
2016-03-16	alpertron	NF-PM1	B1=500000, B2=15000000, E=12
2014-02-07	Never Odd Or Even	F	Factor: 188686661849049690737 / TF: 67-68
2014-01-18	Never Odd Or Even	NF	no factor from 2^69 to 2^70
2014-01-18	Never Odd Or Even	NF	no factor from 2^68 to 2^69
2014-01-18	Never Odd Or Even	NF	no factor from 2^67 to 2^68
2014-01-18	Never Odd Or Even	NF	no factor from 2^66 to 2^67
2014-01-18	Never Odd Or Even	NF	no factor from 2^65 to 2^66
2011-05-07	megavink	NF	no factor from 2^64 to 2^65
2011-05-07	megavink	NF	no factor from 2^63 to 2^64
2011-02-07	Carsten Kossendey	NF-PM1	B1=90000, B2=1507500, E=6
2010-10-27	GrunwalderGIMP	NF	no factor from 2^1 to 2^63
2010-04-23	Architects Cubed	NF	no factor from 2^60 to 2^61