Marin Mersenne 2^P-1
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MnStatusDetails
1981879Composite, with 1 known prime factor. Cofactor is composite.
Factored
FactorDigitsBitsDate
15516578135005396504743912580.42016-02-18 16:28:49
ECM
DigitsB1Curves
2550000280 / 280
30250000106 / 640
Estimated T-Level: 25.8 ⓘ
TF below 2^81 is very unlikely to find new factors due to ECM effort.
LL
StatusDateUserResidueShift
Verified (Factored)Thomas Honold7C91FBE31161DDE80
Verified (Factored)1999-01-02Martijn Otto7C91FBE31161DDE81036691
Verified (Factored)2015-06-27MadPoo7C91FBE31161DDE8400861
PRP
StatusDateUserResidueShiftTypeBase
Verified (Factored)2025-09-02KrieselB98EE8263417F3F9013
PRP Cofactor
StatusDateUserResidueNumber of
known factors		ShiftTypeBase
Verified2017-10-05Oliver Kruse8BD1F2AB8560EEAB1013
Verified2017-11-12ATH8BD1F2AB8560EEAB1115880513
History
DateUserTypeResult
2025-09-03KrieselCERT
PRP Certification
CERT proof power = 6
Proof certified good
2025-09-02KrieselC-PRP
B98EE8263417F3F9
PRP proof power = 6
PRP: Verified (Factored)
Proof certified good
2017-11-12ATHC-PRP
M1981879/1551657813500539650474391 : 8BD1F2AB8560EEAB
PRP: Verified
PRP without proof (not generated)
2017-10-05Oliver KruseC-PRP
M1981879/1551657813500539650474391 : 8BD1F2AB8560EEAB
PRP: Verified
PRP without proof (not generated)
2016-02-23Mark RoseNF
no factor from 2^61 to 2^62
2016-02-23Mark RoseNF
no factor from 2^62 to 2^63
2016-02-23Mark RoseNF
no factor from 2^58 to 2^60
2016-02-18SintaxF-ECM
Factor: 1551657813500539650474391 / (ECM curve 2, B1=50000, B2=5000000)
2015-09-11ramgeisNF
no factor from 2^65 to 2^66
2015-06-27MadPooC-LL
7C91FBE31161DDE8
2015-03-14lycornNF
no factor from 2^64 to 2^65
2015-03-14lycornNF
no factor from 2^63 to 2^64
2011-07-01GrunwalderGIMPNF
no factor from 2^1 to 2^63
2011-01-28kurlyNF-PM1
B1=1000000, B2=30000000, E=12
2009-12-19S485122NF
no factor from 2^60 to 2^61