1 241 951 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
19348102218120956457670631	26	84.0	2018-10-17 18:38:17

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	103 / 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)		David Slowinski	1B4E	0
Verified (Factored)		Steve Sommars	39659E13A40AFB4E	0
Verified (Factored)	2002-08-17	S57483	39659E13A40AFB4E	43198
Verified (Factored)	2016-06-01	MadPoo	39659E13A40AFB4E	1147564

Status	Date	User	Residue	Shift	Type	Base
Verified (Factored)	2025-09-01	Kriesel	1BDC1DDBB5B8A2AE	0	1	3

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	2018-10-17	rucio	1BDC1DDBB5B8A2AE	1	333634	5	3
Verified	2018-10-17	ATH	1BDC1DDBB5B8A2AE	1	96230	5	3

History

Date	User	Type	Result
2025-09-02	EthanD	CERT	PRP Certification CERT proof power = 6 Proof certified good
2025-09-01	Kriesel	C-PRP	1BDC1DDBB5B8A2AE PRP proof power = 6 PRP: Verified (Factored) Proof certified good
2018-10-17	ATH	C-PRP	M1241951/19348102218120956457670631 : 1BDC1DDBB5B8A2AE PRP: Verified PRP without proof (not generated)
2018-10-17	rucio	C-PRP	M1241951/19348102218120956457670631 : 1BDC1DDBB5B8A2AE PRP: Verified PRP without proof (not generated)
2018-10-17	storm5510	F-ECM	Factor: 19348102218120956457670631 / (ECM curve 2, B1=50000, B2=5000000)
2018-09-13	Yxinity	NF	no factor from 2^66 to 2^67
2016-06-01	MadPoo	C-LL	39659E13A40AFB4E
2016-02-23	Mark Rose	NF	no factor from 2^58 to 2^60
2015-09-20	ramgeis	NF	no factor from 2^65 to 2^66
2015-04-05	monst	NF	no factor from 2^64 to 2^65
2015-04-03	omylist	NF	no factor from 2^63 to 2^64
2015-01-05	mikr	NF-PM1	B1=4218475, B2=156083565, E=12
2014-09-23	Joss	NF-PM1	B1=251680
2012-11-11	dbaugh	NF	no factor from 2^62 to 2^63
2011-05-09	megavink	NF	no factor from 2^61 to 2^62
2009-02-17	Sturle Sunde	NF	no factor from 2^60 to 2^61