1 871 029 Exponent Status

PrimeNet Exponent Status

M_n

Status

Details

1871029

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

No factors below 2⁷¹

TF target 2⁶¹

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

P-1

B1 =	25000000
B2 =	84118474440

ECM

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

Estimated T-Level: 25.8 ⓘ

Status	Date	User	Residue	Shift
Verified		Joel Smith	D5422993DD7829C7	0
Verified	1999-01-10	Phil Forrest	D5422993DD7829C7	101816
Verified	2015-07-06	MadPoo	D5422993DD7829C7	1630693

PRP

Status	Date	User	Residue	Shift	Type	Base
Verified	2025-09-02	Kriesel	C74105F701DA191A	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	C74105F701DA191A PRP proof power = 6 PRP: Verified Proof certified good
2024-01-22	kurly	NF-PM1	B1=25000000, B2=84118474440
2023-06-11	Joss	NF-PM1	B1=1871029, B2=17472202020
2023-01-09	Joss	NF-PM1	B1=1871029, B2=1647295650
2022-10-30	masser	NF-PP1	Start=2/7, B1=800000, B2=24000000
2022-10-29	masser	NF-PP1	Start=6/5, B1=400000, B2=10000000
2022-10-27	masser	NF-PP1	Start=197/13, B1=200000, B2=4000000
2018-10-25	Joss	NF-PM1	B1=1871029, B2=205813190, E=12
2018-09-27	Joss	NF-PM1	B1=1871029, B2=187102900, E=12
2018-02-27	Joss	NF-PM1	B1=1871029, B2=111052800, E=12
2018-02-11	Joss	NF-PM1	B1=1871029, B2=55526400, E=12
2018-02-04	Joss	NF-PM1	B1=1871029, B2=27763200, E=12
2018-01-31	Joss	NF-PM1	B1=1871029, B2=13881600, E=12
2017-04-01	Joss	NF-PM1	B1=1388160, B2=13881600, E=12
2017-01-21	Joss	NF-PM1	B1=1156800
2017-01-03	Joss	NF-PM1	B1=864000
2016-12-20	Joss	NF-PM1	B1=720000
2016-10-26	Joss	NF-PM1	B1=600000
2016-02-23	Mark Rose	NF	no factor from 2^58 to 2^60
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
2015-11-04	ramgeis	NF	no factor from 2^70 to 2^71
2015-10-07	Bruno Victal	NF-PM1	B1=500000, B2=15000000, E=12
2015-07-06	MadPoo	C-LL	D5422993DD7829C7
2014-01-04	Never Odd Or Even	NF	no factor from 2^69 to 2^70
2014-01-04	Never Odd Or Even	NF	no factor from 2^68 to 2^69
2014-01-04	Never Odd Or Even	NF	no factor from 2^67 to 2^68
2014-01-04	Never Odd Or Even	NF	no factor from 2^66 to 2^67
2014-01-04	Never Odd Or Even	NF	no factor from 2^65 to 2^66
2012-01-10	markr	NF-PM1	B1=275000, B2=6000000, E=12
2011-05-07	megavink	NF	no factor from 2^64 to 2^65
2011-05-07	megavink	NF	no factor from 2^63 to 2^64
2011-03-08	GrunwalderGIMP	NF	no factor from 2^1 to 2^63
2010-04-10	Architects Cubed	NF	no factor from 2^60 to 2^61

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