is 2 256057 - 1
has 77081 decimal digits
takes 0.002 GHz-days to do one PRP test
Last-known PrimeNet details:
Assigned as ecm on 2022-09-17, 0.0% done, ETC 2022-09-19
-unknown- primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actualunknown30000000100358126969105,417.947373.0247%5,417.947373.0247%73.0247%
PrimeNet2400.000055.0000%2600700000.000114.2541%0.000161.4143%6.4143%
GPU722440.000059.0909%45001100000.000110.1978%0.000163.2627%4.1718%
Difference-440.0000-59.0909%+29995500+10035812586910+5,417.9472+62.8270%+5,417.9472+9.7620%+68.8529%

Known prime factors (2 factors, 156.7 bits, 0.06121311% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
256057160327529991133.90031307
31307
-1313077.939e-91.691e-53.156e-5
256057951852061008478380715360908108159679337122.84018586722116725541202063620758428
22 × 34 × 7 × 17 × 307 × 4229 × 119389 × 1191277 × 2610704407
2021-09-04119127726107044076.244e+111.42052.6323

1 Composite Factors:
exponentprime factorscomposite factordigitsbits*
25605715260808985738012722840866364838460514667953220748156.740
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2021-09-04T22:15:59Oliver KruseOllaptop3000000030000000002437122.8401.9010.0033.80144.067%
2022-04-27T07:16:34Oliver KruseThreadripper-PC3000000010035812696910-
skipped known factor: 16032752999
skipped known factor: 9518520610084783807153609081081596793
--5,418--63.169%


Trial Factoring results:
No TF results for M256057


ECM factoring results:
Total ECM effort:12.309 GHz-days
Estimated T-Level:27.490
DigitsB1CompleteFacMiss
201100036.2170.000%
25500004.9330.721%
302500000.49860.777%
3510000000.04096.100%
4030000000.00399.739%


ECM Summary

B1B2factorcurvesGHz-days
5000050000002812.047
250000250000002418.780
25000036250000210.880
25000038500000140.602


Lucas-Lehmer results:
No L-L results for M256057


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-22T07:47:55Oliver KruseOllaptop
16032752999
7F6C960A0D4475__no
2017-09-22T10:06:36Oliver KruseManual testing
16032752999
7F6C960A0D4475__no
2017-10-12T18:34:34kkmrkkblmbrbkc4.xlarge7F6C960A0D4475__no
2020-04-17T20:17:13Oliver KruseAddPrpType5
16032752999
59DAE1787AF1C8__no
2021-09-04T22:27:46SRJ2877LTOS
16032752999
9518520610084783807153609081081596793
59DAE1787AF1C877no


P-1 factor-bounds graph:
B1 = 30000000, B2 = 10035812696910 (P-1 stage 2)
B1 = 30000000, B2 = 3000000000 (P-1 stage 2)
B1 = 30000000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2022-10-02T07:35:03+00:00