is 2 2708851 - 1
has 815446 decimal digits
takes 0.209 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L907266F9426068CDdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26710.969267.1642%30000080000000.08064.4210%11.049868.6158%1.4517%
PrimeNet2590.028362.7119%120002200000.00262.8447%0.031063.7726%1.0607%
GPU722630.589265.0794%140002200000.00281.6623%0.592065.6599%0.5805%
Difference+4+10.3800+2.0848%+286000+7780000+0.0778+2.7587%+10.4578+2.9560%+2.9560%

Known prime factors (1 factor, 73.0 bits, 0.00269477% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
270885194270599824220500381272272.9971740047714404013
7 × 7682837 × 32355007
2016-02-04768283732355007513.011.01101.7511

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-08T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.298%
2003-11-28T00:00:00Team Prime Ribv4_computers15000217500---0.003--0.921%
2010-12-19T21:41:00Jocelyn LaroucheManual testing2000020000---0.002--0.320%
2010-12-26T14:29:00Jocelyn LaroucheManual testing3000030000---0.003--0.438%
2011-01-18T00:06:00Jocelyn LaroucheManual testing5000050000---0.006--0.627%
2011-04-01T06:27:00James HeinrichWHS3000008000000---0.081--4.421%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:19Mark RoseManual testing21260--0.057--
2009-01-31T03:51:00Sturle Sunderodolfo.ifi260261--0.057--
2012-05-01T04:31:00Grant McCrackenthumper261262--0.113--
2013-01-10T10:18:00dbaughManual testing262263--0.362--
2015-04-13T20:09:00VictordeHollanderManual testing263264--0.725--
2015-04-13T20:09:00VictordeHollanderManual testing264265--1.379--
2016-01-29T11:11:45ramgeisManual testing265266--2.759--


ECM factoring results:

Old Calculation Method

Total ECM effort:1.554 GHz-days
Estimated T-Level:0.750
DigitsB1CurvesCompleteFacMiss
201100015 / 1000.15086.006%
255000015 / 2800.05494.775%

New Calculation Method

Total ECM effort:1.554 GHz-days
Estimated T-Level:0.750
DigitsB1CompleteFacMiss
20110000.48461.639%
25500000.04495.721%
302500000.00399.731%


ECM Summary

B1B2factorcurvesGHz-days
500005000000121.244
50000500000030.311


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-04-23T00:00:00ANONYMOUSv4_computers907266F9426068CD0.209


PRP results:
dateuseridcompidcofactorsres64PRP
2017-10-19T16:07:03Oliver KruseGTX-1
9427059982422050038127
1CC1AC73795E56__no
2017-12-04T18:54:51kkmrkkblmbrbkc4.xlarge
9427059982422050038127
1CC1AC73795E56__no


P-1 factor-bounds graph:
B1 = 300000, B2 = 8000000 (P-1 stage 2)
B1 = 300000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
B1 = 15000, B2 = 217500 (P-1 stage 2)
B1 = 20000 (P-1 stage 1)
B1 = 15000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
102
103
104
105
106
107
102
103
104
105
106
107
108
TF factor-bounds graph:
267
266
265
264
263
262
261
260
250
260
270
280
290
2100
Last modified: 2017-12-04T18:54:51+00:00