1 596 667 Exponent Status

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

PrimeNet Exponent Status

M_n

Status

Details

Composite, with 1 known prime factor. Cofactor is composite.

Factored

Factor	Digits	Bits	Date
4949175810389106848481091951	28	92.0	2013-11-28 14:10:28

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)		Martin Fahlgren	351C7431F4DF5B07	0
Verified (Factored)	1998-12-06	Kent Lee	351C7431F4DF5B07	368396

Status	Date	User	Residue	Shift	Type	Base
Verified (Factored)	2025-09-02	Kriesel	8AD506C88DDD53B3	0	1	3

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	2017-10-02	Oliver Kruse	85311F23FA1A4B65	1	0	1	3
Verified	2017-10-31	kkmrkkblmbrbk	85311F23FA1A4B65	1	996385	1	3

P-1 factors

Date	Factor	B1	B2
2013-11-28	4949175810389106848481091951	980000	28420000

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	8AD506C88DDD53B3 PRP proof power = 6 PRP: Verified (Factored) Proof certified good
2022-03-08	LordJulius	NF	no factor from 2^57 to 2^60
2017-10-31	kkmrkkblmbrbk	C-PRP	M1596667/4949175810389106848481091951 : 85311F23FA1A4B65 PRP: Verified PRP without proof (not generated)
2017-10-02	Oliver Kruse	C-PRP	M1596667/4949175810389106848481091951 : 85311F23FA1A4B65 PRP: Verified PRP without proof (not generated)
2016-03-16	alpertron	NF-PM1	B1=500000, B2=15000000, E=12
2013-11-28	David Campeau	F-PM1	Factor: 4949175810389106848481091951
2011-02-04	James Heinrich	NF-PM1	B1=85000, B2=1445000, E=6
2010-07-04	GrunwalderGIMP	NF	no factor from 2^1 to 2^63
2010-05-03	Architects Cubed	NF	no factor from 2^60 to 2^61