2 605 391 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
4388851316116736197842769	25	81.9	2017-08-19 15:19:09

ECM

Digits	B1	Curves
25	50000	79 / 280

Estimated T-Level: 21.4 ⓘ

TF below 2^66 is very unlikely to find new factors due to ECM effort.

Status	Date	User	Residue	Shift
Verified (Factored)		Francesco Oliveri	07AD62064D31242E	0
Verified (Factored)	1999-07-04	Marco Bresolin	07AD62064D31242E	2491122

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	2017-09-30	alpertron	5F79E3B074883EA9	1	0	1	3
Verified	2017-11-13	Oliver Kruse	5F79E3B074883EA9	1	824962	1	3

P-1 factors

Date	Factor	B1	B2
2017-08-19	4388851316116736197842769	400000	4000000

History

Date	User	Type	Result
2019-07-04	alpertron	NF-PM1	B1=2000000, B2=60000000, E=12
2017-11-13	Oliver Kruse	C-PRP	M2605391/4388851316116736197842769 : 5F79E3B074883EA9 PRP: Verified PRP without proof (not generated)
2017-09-30	alpertron	C-PRP	M2605391/4388851316116736197842769 : 5F79E3B074883EA9 PRP: Verified PRP without proof (not generated)
2017-08-19	Joss	F-PM1	Factor: 4388851316116736197842769 / (P-1, B1=400000, B2=4000000, E=6)
2016-04-25	Joss	NF-PM1	B1=200000, B2=6872948, E=12
2016-02-23	Mark Rose	NF	no factor from 2^59 to 2^60
2016-01-15	ramgeis	NF	no factor from 2^65 to 2^66
2015-02-18	VictordeHollander	NF	no factor from 2^64 to 2^65
2015-02-18	VictordeHollander	NF	no factor from 2^63 to 2^64
2014-10-10	Joss	NF-PM1	B1=124635
2013-01-14	dbaugh	NF	no factor from 2^62 to 2^63
2012-06-24	Sebastian Hornbostel	NF	no factor from 2^61 to 2^62
2010-12-16	markr	NF-PM1	B1=100000, B2=2100000, E=6
2010-11-16	Joss	NF-PM1	B1=20000
2009-01-27	Sturle Sunde	NF	no factor from 2^60 to 2^61