is 2 1252681 - 1
has 377095 decimal digits
takes 0.040 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LBE172ED020769DD5double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26723.720368.6567%300000100000000.03814.1843%23.758369.9682%1.3115%
PrimeNet2560.007762.5000%5500900000.00052.4375%0.008163.4140%0.9140%
GPU722600.122665.0000%5000320000.00030.8558%0.122965.2995%0.2995%
Difference+7+23.5976+3.6567%+295000+9968000+0.0378+3.3286%+23.6354+4.6687%+4.6687%

Known prime factors (1 factor, 61.8 bits, 0.00493333% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
125268140116295980489269271961.7991601217547823
17 × 94189267519
2011-05-0917941892675190.4439235.84440.48

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-02-24T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.238%
2003-11-28T00:00:00eteov4_computers2000002000000---0.014--2.761%
2016-03-17T19:03:45alpertronManual testing3000001000000012---0.038--4.184%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2001-11-14T00:00:00ANONYMOUSv4_computers21257--0.015--
2003-06-01T00:00:00ANONYMOUSv4_computers21258--0.031--
2022-03-07T17:32:03LordJuliusManual testing258260--0.092--
2009-02-18T00:49:00Sturle Sundegilia.ifi260261--0.123--


ECM factoring results:

Old Calculation Method

Total ECM effort:19.218 GHz-days
Estimated T-Level:25.344
DigitsB1CurvesCompleteFacMiss
2011000325 / 1003.2503.815%
2550000325 / 2801.16131.261%
3025000044 / 6400.06993.351%

New Calculation Method

Total ECM effort:19.218 GHz-days
Estimated T-Level:25.344
DigitsB1CompleteFacMiss
201100014.8080.000%
25500001.62019.795%
302500000.13287.678%
3510000000.00999.129%


ECM Summary

B1B2factorcurvesGHz-days
10.00000e+0
50000500000028110.78
25000025000000448.439


Lucas-Lehmer results:
No L-L results for M1252681


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-29T19:02:19Oliver KruseGTX-2
4011629598048926927
1C74941F464C85__no
2017-10-20T19:32:58kkmrkkblmbrbkc4.xlarge
4011629598048926927
1C74941F464C85__no


P-1 factor-bounds graph:
B1 = 300000, B2 = 10000000 (P-1 stage 2)
B1 = 300000 (P-1 stage 1)
B1 = 200000, B2 = 2000000 (P-1 stage 2)
B1 = 200000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
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100
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1010
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TF factor-bounds graph:
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261
260
258
257
250
260
270
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2100
Last modified: 2022-03-07T17:32:03+00:00