Marin Mersenne 2^P-1
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Finding World Record Primes Since 1996

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MnStatusDetails
1873357Composite, with 1 known prime factor. Cofactor is composite.
Factored
FactorDigitsBitsDate
15438050949155035211960.42009-07-22 06:03:02
ECM
DigitsB1Curves
2550000280 / 280
30250000107 / 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)Joel SmithE03DC82B9F43F2A80
Verified (Factored)1999-01-29David W. JamesE03DC82B9F43F2A81656049
PRP
StatusDateUserResidueShiftTypeBase
Verified (Factored)2025-09-02Kriesel222FEB5CCA437044013
PRP Cofactor
StatusDateUserResidueNumber of
known factors		ShiftTypeBase
Verified2017-10-04Oliver KruseEB548CD7FFC533E61013
Verified2017-11-07ATHEB548CD7FFC533E6149100913
History
DateUserTypeResult
2025-09-03Carlos PinhoCERT
PRP Certification
CERT proof power = 6
Proof certified good
2025-09-02KrieselC-PRP
222FEB5CCA437044
PRP proof power = 6
PRP: Verified (Factored)
Proof certified good
2017-11-07ATHC-PRP
M1873357/1543805094915503521 : EB548CD7FFC533E6
PRP: Verified
PRP without proof (not generated)
2017-10-04Oliver KruseC-PRP
M1873357/1543805094915503521 : EB548CD7FFC533E6
PRP: Verified
PRP without proof (not generated)
2016-03-16alpertronNF-PM1
B1=500000, B2=15000000, E=12
2009-07-22James HintzF-ECM
Factor: 1543805094915503521