Marin Mersenne 2^P-1
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Great Internet Mersenne Prime Search
GIMPS
Finding World Record Primes Since 1996

PrimeNet Exponent Status

Exponent Range:










MnStatusDetails
31981Composite, with 1 known prime factor. Cofactor is composite.
Factored
FactorDigitsBitsDate
516906687356331445.6old
ECM
DigitsB1Curves
2550000280 / 280
30250000640 / 640
3510000001566 / 1566
4030000002301 / 4588
Estimated T-Level: 37.5
TF below 2^120 is very unlikely to find new factors due to ECM effort.
PRP Cofactor
StatusDateUserResidueNumber of
known factors
ShiftTypeBase
Verified2017-09-21Oliver Kruse34431F98F56BD70E1013
Verified2017-10-12kkmrkkblmbrbk34431F98F56BD70E12732713
Verified2020-04-17Oliver KruseD4D4D36D57DA5D811463853
Verified2024-07-01kkmrkkblmbrbkD4D4D36D57DA5D811700753
History
DateUserTypeResult
2025-01-02masserNF-PP1
Start=6/5, B1=80000000, B2=79920000000
2024-12-25masserNF-PP1
Start=116/17, B1=80000000, B2=79920000000
2024-12-01masserNF-PP1
Start=2/7, B1=80000000, B2=79920000000
2024-07-01kkmrkkblmbrbkC-PRP
M31981/51690668735633 : D4D4D36D57DA5D81
PRP: Verified
PRP without proof (small exponent)
2022-11-10nordiNF-PM1
B1=3000000000, B2=912626498753970
2022-10-03nordiNF-PM1
B1=3000000000
2020-04-17Oliver KruseC-PRP
M31981/51690668735633 : D4D4D36D57DA5D81
PRP: Verified
PRP without proof (small exponent)
2017-10-12kkmrkkblmbrbkC-PRP
M31981/51690668735633 : 34431F98F56BD70E
PRP: Verified
PRP without proof (not generated)
2017-09-21Oliver KruseC-PRP
M31981/51690668735633 : 34431F98F56BD70E
PRP: Verified
PRP without proof (not generated)
2017-09-21Oliver KruseC-PRP
M31981/51690668735633 : 34431F98F56BD70E
PRP without proof (not generated)
2016-10-08kkmrkkblmbrbkNF-PM1
B1=200000000, B2=5000000000, E=12