1 981 547 Exponent Status

PrimeNet Exponent Status

M_n

Status

Details

Composite: proven not-prime with both PRP and Lucas-Lehmer tests

No factors below 2⁶⁹

TF target 2⁶²

TF below 2^81 is very unlikely to find new factors due to ECM effort.

P-1

B1 =	16000000
B2 =	46185479340

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	106 / 640

Estimated T-Level: 25.8 ⓘ

Status	Date	User	Residue	Shift
Verified		Thomas Honold	1166D43FFA2897D4	0
Verified	1999-01-02	Gordon M. Spence	1166D43FFA2897D4	209652
Verified	2015-06-27	MadPoo	1166D43FFA2897D4	916016

Status	Date	User	Residue	Shift	Type	Base
Verified	2025-09-02	Kriesel	4E6C006DDE77AD13	0	1	3

History

Date	User	Type	Result
2025-09-03	Jurzal	CERT	PRP Certification CERT proof power = 6 Proof certified good
2025-09-02	Kriesel	C-PRP	4E6C006DDE77AD13 PRP proof power = 6 PRP: Verified Proof certified good
2022-10-13	tim s	NF	no factor from 2^68 to 2^69
2022-08-11	masser	NF-PP1	Start=2/7, B1=1400000, B2=49000000
2022-03-07	RichD0	NF-PM1	B1=16000000, B2=46185479340
2019-05-23	chuenkit	NF	no factor from 2^67 to 2^68
2018-11-26	Joss	NF-PM1	B1=1981547, B2=247693375, E=12
2018-05-27	Joss	NF-PM1	B1=1981547, B2=198154700, E=12
2018-03-06	Joss	NF-PM1	B1=1981547, B2=120000000, E=12
2018-02-19	TJAOI	NF	no factor from 2^66 to 2^67
2018-02-15	Joss	NF-PM1	B1=1981547, B2=60000000, E=12
2018-01-24	Joss	NF-PM1	B1=1981547, B2=30000000, E=12
2016-02-23	Mark Rose	NF	no factor from 2^62 to 2^63
2016-02-23	Mark Rose	NF	no factor from 2^61 to 2^62
2016-02-23	Mark Rose	NF	no factor from 2^58 to 2^60
2015-09-11	ramgeis	NF	no factor from 2^65 to 2^66
2015-06-27	MadPoo	C-LL	1166D43FFA2897D4
2015-03-15	lycorn	NF	no factor from 2^64 to 2^65
2015-03-15	lycorn	NF	no factor from 2^63 to 2^64
2011-07-01	GrunwalderGIMP	NF	no factor from 2^1 to 2^63
2011-01-28	kurly	NF-PM1	B1=1000000, B2=30000000, E=12
2009-12-19	S485122	NF	no factor from 2^60 to 2^61

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