is 2 1918181 - 1
has 577431 decimal digits
takes 0.104 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L17C479F7013961BFdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26831.073669.1176%80000003200000001.96659.7389%33.040172.1252%3.0076%
PrimeNet2570.010063.1579%90001700000.00143.0923%0.011464.2972%1.1393%
GPU722610.160165.5738%100001700000.00151.7612%0.161666.1801%0.6063%
Difference+7+30.9135+3.5439%+7990000+319830000+1.9650+7.9776%+32.8785+5.9451%+5.9451%

Known prime factors (1 factor, 75.9 bits, 0.00395843% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1918181719687082660721192417432375.93018759623900474491
18759623900474491
2020-08-021187596239004744915,414.780,399,058150,163,051

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2011-10-04T09:35:00kurlykurlytop100000030000000---0.203--5.685%
2018-01-03T15:29:21mikrS064800000032000000012---1.966--9.739%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2003-01-01T00:00:00ANONYMOUSv4_computers21258--0.020--
2016-02-23T16:28:58Mark RoseManual testing258260--0.060--
2009-06-01T21:03:00Architects Cubedi4l_1260261--0.080--
2016-02-23T16:28:58Mark RoseManual testing261262--0.160--
2011-08-27T22:20:00GrunwalderGIMPManual testing21263--0.832--
2016-02-23T16:28:58Mark RoseManual testing262263--0.512--
2014-12-17T00:51:00Chris SmithManual testing263264--1.024--
2014-12-17T22:50:00lycornManual testing264265--1.948--
2015-09-02T13:37:00ramgeisManual testing265266--3.896--
2017-03-15T08:26:30Smok_bmvManual testing266267--7.791--
2019-04-28T08:32:13chuenkitManual testing267268--15.58--


ECM factoring results:

Old Calculation Method

Total ECM effort:18.411 GHz-days
Estimated T-Level:24.482
DigitsB1CurvesCompleteFacMiss
2011000251 / 1002.5108.025%
2550000251 / 2800.89640.737%

New Calculation Method

Total ECM effort:18.411 GHz-days
Estimated T-Level:24.482
DigitsB1CompleteFacMiss
20110008.3410.024%
25500000.75547.009%
302500000.04795.447%
3510000000.00299.786%


ECM Summary

B1B2factorcurvesGHz-days
5000050000001389.58
50000500000030.208
5000066000001108.619


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-12-21T00:00:00ANONYMOUSv4_computers17C479F7013961BF0.104
2015-06-27T00:56:00MadPooManual testing17C479F7013961BF0.104


PRP results:
dateuseridcompidcofactorsres64PRP
2020-08-02T08:42:17ANONYMOUSdory
71968708266072119241743
972637BD449066E3no
2020-08-02T10:27:56CrypticClueManual testing
71968708266072119241743
972637BD449066E3no


P-1 factor-bounds graph:
B1 = 8000000, B2 = 320000000 (P-1 stage 2)
B1 = 8000000 (P-1 stage 1)
B1 = 1000000, B2 = 30000000 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2022-02-03T11:48:02+00:00