1 962 991 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
4937968133363430789155033	25	82.0	2011-04-08 19:15:57

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	130 / 640

Estimated T-Level: 26.0 ⓘ

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

Status	Date	User	Residue	Shift
Verified (Factored)		Charles R. Bonn	0A5D4B612048816A	0
Verified (Factored)	1999-01-10	Keith Mitchell	0A5D4B612048816A	56533

Status	Date	User	Residue	Shift	Type	Base
Verified (Factored)	2025-09-02	Kriesel	7FFD11C997F08084	0	1	3

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	2017-10-05	Oliver Kruse	C31A82342B250042	1	0	1	3
Verified	2017-11-11	ATH	C31A82342B250042	1	1934926	1	3

History

Date	User	Type	Result
2025-09-03	Jurzal	CERT	PRP Certification CERT proof power = 6 Proof certified good
2025-09-02	Kriesel	C-PRP	7FFD11C997F08084 PRP proof power = 6 PRP: Verified (Factored) Proof certified good
2022-08-16	USAFSS	NF-PM1	B1=176000, B2=172776240
2022-03-09	LordJulius	NF	no factor from 2^1 to 2^60
2017-11-11	ATH	C-PRP	M1962991/4937968133363430789155033 : C31A82342B250042 PRP: Verified PRP without proof (not generated)
2017-10-05	Oliver Kruse	C-PRP	M1962991/4937968133363430789155033 : C31A82342B250042 PRP: Verified PRP without proof (not generated)
2011-04-08	kurly	F-PM1	Factor: 4937968133363430789155033
2010-01-08	S485122	NF	no factor from 2^60 to 2^61