is 2 16808681 - 1
has 5059918 decimal digits
takes 9.191 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LDE037A782E1C9027double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual273113.801065.7534%100000050396313022.51977.0922%136.320768.1823%2.4288%
PrimeNet2650.434061.5385%8000024000000.16364.5230%0.597763.2781%1.7396%
GPU722697.102763.7681%12000032000000.22823.2900%7.330964.9601%1.1920%
Difference+4+106.6983+1.9853%+880000+500763130+22.2915+3.8022%+128.9898+3.2221%+1.2368%

Known prime factors (1 factor, 128.3 bits, 0.00076352% known):
Remaining cofactor is PRP status unknown

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1680868142998630488822375489110566394500284413739128.33812790602215849767001084310659028
22 × 3 × 547 × 1009 × 1733 × 5821 × 85133 × 99643 × 22567859
2022-05-1299643225678597.876e+91.04961.8208

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2002-10-19T00:00:00ANONYMOUSv4_computers1950002973750---0.275--2.242%
2022-05-12T09:01:29alpertronManual testing100000050396313039128.33822.5218.3845.047.092%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2000-12-14T00:00:00ANONYMOUSv4_computers21256--0.001--
2001-04-15T00:00:00Net_Forcev4_computers21259--0.005--
2001-07-17T00:00:00ANONYMOUSv4_computers21265--0.434--
2016-03-16T02:24:28Mark RoseManual testing265266--0.445--
2014-09-15T21:08:00NesowaManual testing266267--0.889--
2018-03-11T22:57:22ramgeisManual testing267268--1.778--
2018-03-11T22:57:22ramgeisManual testing268269--3.557--
2020-05-24T22:47:43lycornManual testing269270--7.113--
2021-09-01T08:41:58lycornManual testing270271--14.23--
2021-09-19T14:54:37-Anonymous-Manual testing271272--28.45--
2021-11-26T12:05:26-Anonymous-Manual testing272273--56.91--


ECM factoring results:
Total ECM effort:0.831 GHz-days
Estimated T-Level:0.192
DigitsB1CompleteFacMiss
20110000.03896.227%
25500000.00499.645%


ECM Summary

B1B2factorcurvesGHz-days
50000500000010.831


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2002-11-24T00:00:00ANONYMOUSv4_computersDE037A782E1C90279.191
2006-04-14T00:00:00ebravickv4_computersDE037A782E1C90279.191


PRP results:
No PRP results for M16808681


P-1 factor-bounds graph:
B1 = 1000000, B2 = 503963130 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
B1 = 195000, B2 = 2973750 (P-1 stage 2)
B1 = 195000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2022-05-12T10:14:22+00:00