220 447 Exponent Status

PrimeNet Exponent Status

M_n

Status

Details

Composite: proven not-prime with Lucas-Lehmer test

No factors below 2⁶⁷

TF target 2⁴⁴

TF below 2^105 is very unlikely to find new factors due to ECM effort.

P-1

B1 =	138000000
B2 =	5678068856460

ECM

Estimated T-Level: 33.2 ⓘ

Status	Date	User	Residue	Shift
Verified		Unknown	75CC	0
Verified		Tom Cattrall	D8E093C70ED5F5CC	0
Verified		Brian J. Beesley	D8E093C70ED5F5CC	0
Verified		Eivind Triel	D8E093C70ED5F5CC	89493
Verified	2016-06-01	MadPoo	D8E093C70ED5F5CC	11421

Assigned

Assigned	User	Work Type	Stage	% Done	Updated	Expired
2025-09-14	Oliver Kruse	factor ECM small	C41S1	48.92 %	2025-09-15
2025-08-25	-Anonymous-	factor ECM small		0.00 %	2025-08-25

History

Date	User	Type	Result
2025-03-12	tim s	NF	no factor from 2^66 to 2^67
2023-02-17	masser	NF-PP1	Start=6/5, B1=30000000, B2=990000000
2023-02-11	masser	NF-PP1	Start=177/59, B1=30000000, B2=840000000
2023-02-05	masser	NF-PP1	Start=2/7, B1=30000000, B2=990000000
2022-06-05	Sid & Andy	NF-PM1	B1=138000000, B2=5678068856460
2022-03-07	LordJulius	NF	no factor from 2^54 to 2^55
2019-12-18	Gordon Spence	NF	no factor from 2^65 to 2^66
2019-04-18	alex	NF-PM1	B1=100000000, B2=2000000000, E=12
2018-03-02	Gordon Spence	NF	no factor from 2^64 to 2^65
2016-09-06	Joss	NF-PM1	B1=20000000, B2=800000000, E=12
2016-09-02	Joss	NF-PM1	B1=20000000, B2=400000000, E=12
2016-06-01	MadPoo	C-LL	D8E093C70ED5F5CC
2016-02-23	Mark Rose	NF	no factor from 2^57 to 2^58
2016-01-23	Gordon Spence	NF	no factor from 2^63 to 2^64
2016-01-23	Gordon Spence	NF	no factor from 2^62 to 2^63
2015-06-28	snme2pm1	NF	no factor from 2^61 to 2^62
2013-07-23	lycorn	NF	no factor from 2^60 to 2^61
2013-06-28	BloodIce	NF-PM1	B1=20000000, B2=200000000, E=12
2012-05-29	Joss	NF-PM1	B1=7079833
2011-01-29	Joss	NF-PM1	B1=5000000
2009-01-29	Sturle Sunde	NF	no factor from 2^59 to 2^60
2009-01-01	Sturle Sunde	NF	no factor from 2^58 to 2^59

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