12 255 877 Exponent Status

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

PrimeNet Exponent Status

M_n

Status

Details

Factored

Factor	Digits	Bits	Date
1265924948554441300149755767	28	90.0	2021-12-21 11:40:53

ECM

Digits	B1	Curves
25	50000	2 / 280

Estimated T-Level: 20.0 ⓘ

TF below 2^62 is very unlikely to find new factors due to ECM effort.

Status	Date	User	Residue	Shift
Verified (Factored)	2001-07-17	Mark	1DC5ADBA997518C2	2800836
Verified (Factored)	2004-06-21	Marc Getty / Phil Fizur	1DC5ADBA997518C2	3105524

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	2022-02-20	GAN	541B50BD5031F188	1	7441874	5	3

P-1 factors

Date	Factor	B1	B2
2021-12-21	1265924948554441300149755767	1000000	2250268020

History

Date	User	Type	Result
2022-02-20	march	CERT	PRP Certification Proof certified good
2022-02-20	GAN	C-PRP	M12255877/1265924948554441300149755767 : 541B50BD5031F188 PRP proof power = 8 PRP: Verified Proof certified good
2021-12-21	Luminescence	F-PM1	Factor: 1265924948554441300149755767 / (P-1, B1=1000000, B2=2250268020)
2021-10-22	-Anonymous-	NF	no factor from 2^71 to 2^72
2021-07-29	ZacHFX	NF	no factor from 2^70 to 2^71
2021-07-29	ZacHFX	NF	no factor from 2^69 to 2^70
2017-11-03	ramgeis	NF	no factor from 2^68 to 2^69
2015-07-25	Tha	NF	no factor from 2^67 to 2^68
2015-05-13	Sid & Andy	NF-PM1	B1=125000, B2=2093750, E=6
2015-03-05	Tha	NF	no factor from 2^66 to 2^67
2013-09-29	Nesowa	NF	no factor from 2^65 to 2^66
2013-08-12	lycorn	NF	no factor from 2^64 to 2^65