is 2 2178571 - 1
has 655816 decimal digits
takes 0.143 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
1 primality tests remaining
ResidueStatus
L-LE56AFC3A6618142Edouble-checked
PRP061E060AEE9A11__verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26827.359667.6471%50000002000000001.48968.9489%28.849270.5423%2.8952%
PrimeNet2580.017662.0690%100001800000.00182.8579%0.019563.1530%1.0840%
GPU722620.282064.5161%110001600000.00181.5685%0.283865.0727%0.5566%
Difference+6+27.0776+3.1309%+4989000+199840000+1.4877+7.3803%+28.5654+5.4696%+5.4696%

Known prime factors (1 factor, 69.8 bits, 0.00320327% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
217857110174625983071059087772269.785233516052106428
22 × 3 × 7 × 132 × 16449426043
2020-10-231691644942604356.79685.442159.58

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-03-07T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.226%
2010-11-05T01:17:00Jocelyn LaroucheManual testing1500015000---0.001--0.198%
2010-11-08T01:30:00Jocelyn LaroucheManual testing3000030000---0.003--0.354%
2011-01-14T16:45:00markrtiny900001620000---0.017--2.204%
2014-06-21T17:25:00Jocelyn LaroucheManual testing119462119462---0.011--0.890%
2014-10-06T21:12:00Jocelyn LaroucheManual testing148924148924---0.014--1.007%
2015-12-22T14:03:57HBendtzManual testing7000002100000012---0.172--5.206%
2019-11-28T05:38:31BigBrotherWinston30000009000000012---0.738--7.643%
2019-11-30T00:52:50mikrMSI500000020000000012---1.490--8.949%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-01-29T00:00:00Dry Creek Photov4_computers21258--0.018--
2016-02-23T16:29:07Mark RoseManual testing258260--0.053--
2009-01-04T20:49:00Sturle Sundegassmann.ifi260261--0.071--
2009-01-08T00:25:00Sturle Sundegolan.ifi261262--0.141--
2013-09-09T08:40:00ramgeisManual testing262263--0.451--
2015-03-25T10:09:00VictordeHollanderManual testing263264--0.901--
2015-03-25T10:09:00VictordeHollanderManual testing264265--1.715--
2016-01-02T13:50:58ramgeisManual testing265266--3.430--
2016-11-17T17:00:13Gordon SpenceManual testing266267--6.860--
2019-04-22T13:11:42TJAOIManual testing267268--13.72--


ECM factoring results:

Old Calculation Method

Total ECM effort:10.516 GHz-days
Estimated T-Level:22.196
DigitsB1CurvesCompleteFacMiss
2011000123 / 1001.23029.049%
2550000123 / 2800.43964.399%

New Calculation Method

Total ECM effort:10.516 GHz-days
Estimated T-Level:22.196
DigitsB1CompleteFacMiss
20110003.9681.892%
25500000.35969.865%
302500000.02297.816%
3510000000.00199.899%


ECM Summary

B1B2factorcurvesGHz-days
50000500000012010.26
50000500000030.256


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-07-27T00:00:00Stephen Woodv4_computersE56AFC3A6618142E0.143
2018-04-13T07:11:44kkmrkkblmbrbkoldE56AFC3A6618142E0.143


PRP results:
dateuseridcompidcofactorsres64PRP
2020-10-23T15:42:30mrhp
1017462598307105908777
061E060AEE9A11__no


P-1 factor-bounds graph:
B1 = 5000000, B2 = 200000000 (P-1 stage 2)
B1 = 3000000, B2 = 90000000 (P-1 stage 2)
B1 = 5000000 (P-1 stage 1)
B1 = 3000000 (P-1 stage 1)
B1 = 700000, B2 = 21000000 (P-1 stage 2)
B1 = 700000 (P-1 stage 1)
B1 = 90000, B2 = 1620000 (P-1 stage 2)
B1 = 148924 (P-1 stage 1)
B1 = 119462 (P-1 stage 1)
B1 = 90000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
B1 = 15000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
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107
101
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1010
1011
TF factor-bounds graph:
268
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266
265
264
263
262
261
260
258
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260
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2100
Last modified: 2020-10-23T15:42:30+00:00