is 2 2681681 - 1
has 807267 decimal digits
takes 0.207 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LE5E1107CBD1941C4double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26711.080367.1642%2000000600000000.57797.7023%11.658269.6933%2.5291%
PrimeNet2590.028662.7119%120002200000.00262.8395%0.031263.7707%1.0588%
GPU722630.595265.0794%130002200000.00271.6225%0.597965.6460%0.5666%
Difference+4+10.4852+2.0848%+1987000+59780000+0.5752+6.0798%+11.0603+4.0473%+4.0473%

Known prime factors (1 factor, 81.7 bits, 0.00304616% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
268168138961803621528461828549212581.688726443667638478660
22 × 3 × 5 × 13 × 109 × 307 × 27831875069
2018-06-0930727831875069329,668169.82317.18

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-08T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.297%
2003-11-28T00:00:00Team Prime Ribv4_computers15000217500---0.003--0.919%
2010-11-20T12:24:00Jocelyn LaroucheManual testing2000020000---0.002--0.319%
2010-12-05T07:36:00markrtiny1050002283750---0.025--2.866%
2016-06-14T12:42:16Jocelyn LaroucheManual testing15182745675006---0.044--3.558%
2016-12-16T17:35:07Jocelyn Larouchelow 4M182192182192---0.020--1.327%
2016-12-29T21:56:33Jocelyn Larouchelow 4M218630218630---0.024--1.453%
2017-03-03T01:10:48Jocelyn Larouchelow 4M31482731482706---0.053--3.632%
2018-02-20T11:48:59Jocelyn Larouchelow 4M377792377792---0.042--1.873%
2019-07-04T12:48:23alpertronManual testing20000006000000012---0.578--7.702%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:19Mark RoseManual testing21260--0.057--
2009-01-26T06:53:00Sturle Sundegaudi.ifi260261--0.057--
2012-05-14T21:23:00markroldgamer261262--0.115--
2013-01-14T12:26:00dbaughManual testing262263--0.366--
2015-02-23T17:25:00VictordeHollanderManual testing263264--0.732--
2015-02-23T17:25:00VictordeHollanderManual testing264265--1.393--
2016-01-25T14:29:40ramgeisManual testing265266--2.787--
2017-09-13T08:55:32Gordon SpenceManual testing266267--5.573--


ECM factoring results:

Old Calculation Method

Total ECM effort:3.001 GHz-days
Estimated T-Level:1.450
DigitsB1CurvesCompleteFacMiss
201100029 / 1000.29074.717%
255000029 / 2800.10490.144%

New Calculation Method

Total ECM effort:3.001 GHz-days
Estimated T-Level:1.450
DigitsB1CompleteFacMiss
20110000.93539.240%
25500000.08591.893%
302500000.00599.481%


ECM Summary

B1B2factorcurvesGHz-days
500005000000272.794
50000500000020.207


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-05-30T00:00:00ANONYMOUSv4_computersE5E1107CBD1941C40.207


PRP results:
dateuseridcompidcofactorsres64PRP
2018-06-10T18:54:11Luigi MorelliImac
3896180362152846182854921
3BA591584DED7D__no
2018-06-11T02:50:36Oliver KruseGTX-3
3896180362152846182854921
3BA591584DED7D__no


P-1 factor-bounds graph:
B1 = 2000000, B2 = 60000000 (P-1 stage 2)
B1 = 2000000 (P-1 stage 1)
B1 = 314827, B2 = 3148270 (P-1 stage 2)
B1 = 151827, B2 = 4567500 (P-1 stage 2)
B1 = 377792 (P-1 stage 1)
B1 = 314827 (P-1 stage 1)
B1 = 105000, B2 = 2283750 (P-1 stage 2)
B1 = 218630 (P-1 stage 1)
B1 = 182192 (P-1 stage 1)
B1 = 151827 (P-1 stage 1)
B1 = 105000 (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)
101
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107
101
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1010
1011
TF factor-bounds graph:
267
266
265
264
263
262
261
260
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270
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2100
Last modified: 2019-07-04T12:48:23+00:00