1 622 773 Exponent Status

Great Internet Mersenne Prime Search
GIMPS
Finding World Record Primes Since 1996

PrimeNet Exponent Status

M_n

Status

Details

Composite, with 1 known prime factor. Cofactor is composite.

Factored

Factor	Digits	Bits	Date
161486403035097862086406199	27	87.1	2016-09-29 17:24:13

ECM

Digits	B1	Curves
25	50000	280 / 280
30	250000	107 / 640

Estimated T-Level: 25.8 ⓘ

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

Status	Date	User	Residue	Shift
Verified (Factored)		The Grebelius Family	3CF7AAC718604F2C	0
Verified (Factored)	1998-11-07	Nuutti Kuosa	3CF7AAC718604F2C	746640
Verified (Factored)	2015-06-29	MadPoo	3CF7AAC718604F2C	546118

Status	Date	User	Residue	Shift	Type	Base
Verified (Factored)	2025-09-02	Kriesel	CC9B1A735EAC8D69	0	1	3

Status	Date	User	Residue	Number of known factors	Shift	Type	Base
Verified	2017-10-02	Oliver Kruse	A121A322CE56BFEE	1	0	1	3
Verified	2017-11-01	kkmrkkblmbrbk	A121A322CE56BFEE	1	1497948	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	CC9B1A735EAC8D69 PRP proof power = 6 PRP: Verified (Factored) Proof certified good
2017-11-01	kkmrkkblmbrbk	C-PRP	M1622773/161486403035097862086406199 : A121A322CE56BFEE PRP: Verified PRP without proof (not generated)
2017-10-02	Oliver Kruse	C-PRP	M1622773/161486403035097862086406199 : A121A322CE56BFEE PRP: Verified PRP without proof (not generated)
2016-09-29	bam	F-ECM	Factor: 161486403035097862086406199 / (ECM curve 2, B1=50000, B2=5000000)
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
2015-06-29	MadPoo	C-LL	3CF7AAC718604F2C
2015-04-30	monst	NF	no factor from 2^64 to 2^65
2015-04-29	omylist	NF	no factor from 2^63 to 2^64
2011-12-01	BigBrother	NF-PM1	B1=1000000, B2=20000000, E=12
2010-08-13	GrunwalderGIMP	NF	no factor from 2^1 to 2^63
2010-05-05	Architects Cubed	NF	no factor from 2^60 to 2^61