2 155 207 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
399857400666826281171267056543521609	36	118.3	2016-04-09 18:54:43

ECM

Digits	B1	Curves
25	50000	109 / 280

Estimated T-Level: 21.9 ⓘ

TF below 2^68 is very unlikely to find new factors due to ECM effort.

Status	Date	User	Residue	Shift
Verified (Factored)		Steffen Haugk	BDC95C5E47614A52	0
Verified (Factored)	1999-02-14	Lars Lindley	BDC95C5E47614A52	1297223

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	2017-10-08	Oliver Kruse	E8467A94D8FA093D	1	0	1	3
Verified	2017-11-18	kkmrkkblmbrbk	E8467A94D8FA093D	1	613034	1	3

P-1 factors

Date	Factor	B1	B2
2016-04-09	399857400666826281171267056543521609	360000	6480000

History

Date	User	Type	Result
2023-01-28	USAFSS	NF-PM1	B1=288000, B2=309861090
2017-11-18	kkmrkkblmbrbk	C-PRP	M2155207/399857400666826281171267056543521609 : E8467A94D8FA093D PRP: Verified PRP without proof (not generated)
2017-10-08	Oliver Kruse	C-PRP	M2155207/399857400666826281171267056543521609 : E8467A94D8FA093D PRP: Verified PRP without proof (not generated)
2016-04-09	Joss	F-PM1	Factor: 399857400666826281171267056543521609 / (P-1, B1=360000, B2=6480000, E=12)
2016-03-22	Joss	NF-PM1	B1=269605
2016-02-23	Mark Rose	NF	no factor from 2^58 to 2^60
2015-12-30	ramgeis	NF	no factor from 2^65 to 2^66
2015-03-22	VictordeHollander	NF	no factor from 2^64 to 2^65
2015-03-22	VictordeHollander	NF	no factor from 2^63 to 2^64
2014-10-01	Joss	NF-PM1	B1=149781
2013-09-08	ramgeis	NF	no factor from 2^62 to 2^63
2011-01-24	markr	NF-PM1	B1=120000, B2=2340000, E=6
2011-01-15	Joss	NF-PM1	B1=50000
2010-12-30	Joss	NF-PM1	B1=30000
2010-11-03	Joss	NF-PM1	B1=20000
2009-01-07	Sturle Sunde	NF	no factor from 2^61 to 2^62
2009-01-04	Sturle Sunde	NF	no factor from 2^60 to 2^61