1 026 887 Exponent Status

PrimeNet Exponent Status

M_n

Status

Details

1026887

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

No factors below 2⁷¹

TF target 2⁶⁰

TF below 2^83 is very unlikely to find new factors due to ECM effort.

P-1

B1 =	28000000
B2 =	85350951840

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	177 / 640

Estimated T-Level: 26.4 ⓘ

Status	Date	User	Residue	Shift
Verified		David Slowinski	80A	0
Verified		Peter Frostad	301AEC56E456E80A	0
Verified	2002-02-03	S57483	301AEC56E456E80A	684954
Verified	2016-06-01	MadPoo	301AEC56E456E80A	661463

PRP

Status	Date	User	Residue	Shift	Type	Base
Verified	2020-11-02	Ethan O'Connor	CEFB8BDC393E7936	0	1	3
Verified	2025-09-01	Kriesel	CEFB8BDC393E7936	0	1	3

History

Date	User	Type	Result
2025-09-01	ElectricBill	CERT	PRP Certification CERT proof power = 6 Proof certified good
2025-09-01	Kriesel	C-PRP	CEFB8BDC393E7936 PRP proof power = 6 PRP: Verified Proof certified good
2022-05-26	axn	NF-PM1	B1=28000000, B2=85350951840
2022-01-31	Numberwang	NF-PM1	B1=107000, B2=2525853330
2020-11-02	Franklin Webber	CERT	PRP Certification CERT proof power = 8 Proof certified good
2020-11-02	Ethan O'Connor	C-PRP	CEFB8BDC393E7936 PRP proof power = 8 PRP: Verified Proof certified good
2018-11-19	Joss	NF-PM1	B1=4451352, B2=206404287
2018-10-21	Joss	NF-PM1	B1=4451352, B2=205377400, E=12
2018-05-01	Joss	NF-PM1	B1=4451352, B2=102688700, E=12
2018-02-22	Joss	NF-PM1	B1=4451352, B2=85790972, E=12
2018-02-22	Joss	NF-PM1	B1=4451352, B2=42895486, E=12
2016-10-13	Joss	NF-PM1	B1=4431352, B2=42895486, E=6
2016-07-27	Joss	NF-PM1	B1=4431352, B2=35450816, E=12
2016-06-18	Joss	NF-PM1	B1=4431352, B2=17725408, E=12
2016-06-17	Joss	NF-PM1	B1=4431352, B2=8862704, E=6
2016-06-01	MadPoo	C-LL	301AEC56E456E80A
2016-05-15	Numberwang	NF-PM1	B1=10000, B2=250000
2016-02-23	Mark Rose	NF	no factor from 2^58 to 2^60
2015-08-11	Joss	NF-PM1	B1=4431352
2014-12-02	Joss	NF-PM1	B1=1026887
2014-10-17	Joss	NF-PM1	B1=325006
2014-07-18	Joss	NF-PM1	B1=262503
2014-04-01	Never Odd Or Even	NF	no factor from 2^70 to 2^71
2013-07-28	Never Odd Or Even	NF	no factor from 2^69 to 2^70
2013-07-28	Never Odd Or Even	NF	no factor from 2^68 to 2^69
2013-04-13	Never Odd Or Even	NF	no factor from 2^67 to 2^68
2013-04-13	Never Odd Or Even	NF	no factor from 2^66 to 2^67
2013-04-13	Never Odd Or Even	NF	no factor from 2^65 to 2^66
2013-04-13	Never Odd Or Even	NF	no factor from 2^64 to 2^65
2012-01-01	bcp19	NF-PM1	B1=200000, B2=10000000, E=12
2010-11-23	Michael C	NF	no factor from 2^63 to 2^64
2010-11-23	Michael C	NF	no factor from 2^62 to 2^63
2010-11-07	Michael C	NF	no factor from 2^61 to 2^62
2009-02-15	Sturle Sunde	NF	no factor from 2^60 to 2^61

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