1 822 781 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
2822519467496732207	19	61.3	2016-04-15 11:44:25
76360913238092655241	20	66.0	2009-07-18 03:21:59

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	106 / 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)		Ken Kriesel	B65E9FBC01EF52B1	0
Verified (Factored)	1998-12-21	Simon Ting	B65E9FBC01EF52B1	501140

Status	Date	User	Residue	Shift	Type	Base
Verified (Factored)	2025-09-02	Kriesel	8C379C6EDB3FD337	0	1	3

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	2017-10-05	Oliver Kruse	D2A1A407E37ED32C	2	0	1	3
Verified	2017-11-11	kkmrkkblmbrbk	D2A1A407E37ED32C	2	1286183	1	3

History

Date	User	Type	Result
2025-09-03	Oliver Kruse	CERT	PRP Certification CERT proof power = 6 Proof certified good
2025-09-02	Kriesel	C-PRP	8C379C6EDB3FD337 PRP proof power = 6 PRP: Verified (Factored) Proof certified good
2022-03-09	LordJulius	NF	no factor from 2^1 to 2^61
2022-03-08	LordJulius	NF	no factor from 2^58 to 2^61
2017-11-11	kkmrkkblmbrbk	C-PRP	M1822781/2822519467496732207/76360913238092655241 : D2A1A407E37ED32C PRP: Verified PRP without proof (not generated)
2017-10-05	Oliver Kruse	C-PRP	M1822781/76360913238092655241/2822519467496732207 : D2A1A407E37ED32C PRP: Verified PRP without proof (not generated)
2017-10-03	Oliver Kruse	C-PRP	M1822781/76360913238092655241/2822519467496732207 : D2A1A407E37ED32C PRP without proof (not generated)
2016-04-15	TJAOI	F	Factor: 2822519467496732207 / TF: 61-62
2016-03-16	alpertron	NF-PM1	B1=500000, B2=15000000, E=12
2009-07-18	SubPrime	F-ECM	Factor: 76360913238092655241