2 197 561 Exponent Status

PrimeNet Exponent Status

M_n

Status

Details

Composite: proven not-prime with Lucas-Lehmer test

No factors below 2⁶⁹

TF target 2⁶²

TF below 2^82 is very unlikely to find new factors due to ECM effort.

P-1

B1 =	10000000
B2 =	20645768220

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	165 / 640

Estimated T-Level: 26.3 ⓘ

Status	Date	User	Residue	Shift
Verified		Michael Bertrand	4A6EAACC9206FF2D	0
Verified	1999-02-07	Greg Hewgill	4A6EAACC9206FF2D	1369909
Verified	2018-04-15	kkmrkkblmbrbk	4A6EAACC9206FF2D	1392178

History

Date	User	Type	Result
2025-04-05	Joss	NF-PM1	B1=10000000, B2=20645768220
2025-03-17	Joss	NF-PM1	B1=10000000, B2=10402895580
2023-01-02	Architects Cubed	NF-PM1	B1=5000000, B2=9896994030
2021-07-15	TJAOI	NF	no factor from 2^68 to 2^69
2019-04-01	TJAOI	NF	no factor from 2^67 to 2^68
2018-04-15	kkmrkkblmbrbk	C-LL	4A6EAACC9206FF2D
2018-03-24	mikr	NF-PM1	B1=2500000, B2=125000000, E=12
2016-12-01	Gordon Spence	NF	no factor from 2^66 to 2^67
2016-02-23	Mark Rose	NF	no factor from 2^58 to 2^60
2016-02-03	Joss	NF-PM1	B1=583200, B2=5832000, E=6
2016-01-04	ramgeis	NF	no factor from 2^65 to 2^66
2015-04-25	VictordeHollander	NF	no factor from 2^64 to 2^65
2015-04-25	VictordeHollander	NF	no factor from 2^63 to 2^64
2014-10-13	Joss	NF-PM1	B1=148414
2014-07-04	Joss	NF-PM1	B1=119207
2013-12-04	LaurV	NF	no factor from 2^62 to 2^63
2011-01-10	markr	NF-PM1	B1=90000, B2=1620000, E=6
2010-11-09	Joss	NF-PM1	B1=30000
2010-11-05	Joss	NF-PM1	B1=15000
2009-01-10	Sturle Sunde	NF	no factor from 2^61 to 2^62
2009-01-02	Sturle Sunde	NF	no factor from 2^60 to 2^61

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