1 873 271 Exponent Status

PrimeNet Exponent Status

M_n

Status

Details

1873271

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 =	69189473430

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	9933DC80C5768999	0
Verified	1999-01-10	John T Marshall	9933DC80C5768999	607805
Verified	2016-04-30	kkmrkkblmbrbk	9933DC80C5768999	1337286

PRP

Status	Date	User	Residue	Shift	Type	Base
Verified	2025-09-02	Kriesel	EC8E8911893EC83B	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	EC8E8911893EC83B PRP proof power = 6 PRP: Verified Proof certified good
2024-01-29	Joss	NF-PM1	B1=6194262, B2=12912206580
2024-01-27	kurly	NF-PM1	B1=25000000, B2=69189473430
2023-06-11	Joss	NF-PM1	B1=1873271, B2=17472409500
2023-01-09	Joss	NF-PM1	B1=1873271, B2=1647535890
2022-10-30	masser	NF-PP1	Start=2/7, B1=800000, B2=25600000
2022-10-29	masser	NF-PP1	Start=6/5, B1=400000, B2=10800000
2022-10-27	masser	NF-PP1	Start=112/19, B1=200000, B2=4400000
2019-06-17	TJAOI	NF	no factor from 2^67 to 2^68
2018-10-25	Joss	NF-PM1	B1=1873271, B2=206059810, E=12
2018-09-27	Joss	NF-PM1	B1=1873271, B2=187327100, E=12
2018-02-27	Joss	NF-PM1	B1=1873271, B2=111052800, E=12
2018-02-19	TJAOI	NF	no factor from 2^66 to 2^67
2018-02-10	Joss	NF-PM1	B1=1873271, B2=55526400, E=12
2018-02-04	Joss	NF-PM1	B1=1873271, B2=27763200, E=12
2018-01-16	Joss	NF-PM1	B1=1873271, B2=13881600, E=12
2017-04-21	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
2016-11-13	Joss	NF-PM1	B1=600000
2016-04-30	kkmrkkblmbrbk	C-LL	9933DC80C5768999
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
2015-10-07	Bruno Victal	NF-PM1	B1=500000, B2=15000000, E=12
2015-09-11	ramgeis	NF	no factor from 2^65 to 2^66
2015-05-08	snme2pm1	NF	no factor from 2^64 to 2^65
2015-05-08	snme2pm1	NF	no factor from 2^63 to 2^64
2012-01-11	markr	NF-PM1	B1=275000, B2=6000000, E=12
2011-03-08	GrunwalderGIMP	NF	no factor from 2^1 to 2^63
2010-04-11	Architects Cubed	NF	no factor from 2^60 to 2^61

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