1 631 761 Exponent Status

PrimeNet Exponent Status

M_n

Status

Details

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

No factors below 2⁶⁸

TF target 2⁶¹

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

P-1

B1 =	25000000
B2 =	611144523990

ECM

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

Estimated T-Level: 25.8 ⓘ

Status	Date	User	Residue	Shift
Verified		Olaf Kortlueke	34027B980294EA0F	0
Verified	1998-11-21	Roger Smith	34027B980294EA0F	1249752
Verified	2015-06-27	MadPoo	34027B980294EA0F	218631

Status	Date	User	Residue	Shift	Type	Base
Verified	2025-09-02	Kriesel	DE510911D3D614A5	0	1	3

History

Date	User	Type	Result
2025-09-03	Carlos Pinho	CERT	PRP Certification CERT proof power = 6 Proof certified good
2025-09-02	Kriesel	C-PRP	DE510911D3D614A5 PRP proof power = 6 PRP: Verified Proof certified good
2022-11-21	Naegi Makoto	NF-PM1	B1=25000000, B2=611144523990
2019-08-06	TJAOI	NF	no factor from 2^67 to 2^68
2018-02-12	VictordeHollander	NF-PM1	B1=10000000, B2=200000000, E=12
2018-02-07	Joss	NF-PM1	B1=2000000, B2=40000000, E=12
2017-11-10	TJAOI	NF	no factor from 2^66 to 2^67
2017-09-10	Joss	NF-PM1	B1=2000000, B2=20000000, 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
2015-10-11	ramgeis	NF	no factor from 2^65 to 2^66
2015-06-27	MadPoo	C-LL	34027B980294EA0F
2015-05-03	monst	NF	no factor from 2^64 to 2^65
2015-05-02	omylist	NF	no factor from 2^63 to 2^64
2012-03-01	Axon	NF-PM1	B1=1000000, B2=20000000, E=12
2012-03-01	Axon	NF-PM1	B1=1000000, B2=8000000, E=12
2012-02-29	Axon	NF-PM1	B1=1000000
2012-02-29	Axon	NF-PM1	B1=900000
2012-02-29	Axon	NF-PM1	B1=800000
2012-02-29	Axon	NF-PM1	B1=700000
2012-02-29	Axon	NF-PM1	B1=600000
2012-02-29	Axon	NF-PM1	B1=500000
2012-02-29	Axon	NF-PM1	B1=400000
2012-02-29	Axon	NF-PM1	B1=300000
2012-02-29	Axon	NF-PM1	B1=200000
2012-02-29	Axon	NF-PM1	B1=100000
2010-09-13	GrunwalderGIMP	NF	no factor from 2^1 to 2^63
2010-04-30	Architects Cubed	NF	no factor from 2^60 to 2^61

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