is 2 2250257 - 1
has 677395 decimal digits
takes 0.148 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LC1A6FA8285630C8Bdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26713.204767.1642%58905058905000.08374.3765%13.288468.6012%1.4370%
PrimeNet2580.017162.0690%100001900000.00192.9163%0.019063.1751%1.1062%
GPU722620.273064.5161%110001900000.00201.6600%0.275065.1052%0.5890%
Difference+5+12.9317+2.6481%+578050+5700500+0.0817+2.7165%+13.0134+3.4961%+3.4961%

Known prime factors (1 factor, 82.1 bits, 0.00365053% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
225025753517550967579326030795432582.1461189143083825077003
7 × 25741 × 47419 × 139174051
2017-06-2847419139174051784,1430.72721.3502

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-04-03T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.282%
2010-10-20T17:31:00Oscar Östlin7501175011---0.007--0.783%
2011-01-14T14:27:00Oscar Östlin850001636250---0.016--2.478%
2014-06-01T23:28:00Jocelyn LaroucheManual testing113523113523---0.011--0.999%
2014-10-03T21:04:00Jocelyn LaroucheManual testing142046142046---0.014--1.130%
2016-01-17T15:05:41Jocelyn LaroucheManual testing58905058905006---0.084--4.376%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:10Mark RoseManual testing21260--0.068--
2009-01-11T09:08:00Sturle Sundewright.ifi260261--0.068--
2012-05-04T09:48:00Sebastian HornbostelManual testing261262--0.137--
2013-01-23T08:24:00dbaughManual testing262263--0.436--
2015-03-10T10:44:00VictordeHollanderManual testing263264--0.872--
2015-03-10T10:44:00VictordeHollanderManual testing264265--1.660--
2015-10-27T09:37:31ramgeisManual testing265266--3.321--
2017-01-05T21:20:48Gordon SpenceManual testing266267--6.642--


ECM factoring results:

Old Calculation Method

Total ECM effort:2.576 GHz-days
Estimated T-Level:1.500
DigitsB1CurvesCompleteFacMiss
201100030 / 1000.30073.970%
255000030 / 2800.10789.823%

New Calculation Method

Total ECM effort:2.576 GHz-days
Estimated T-Level:1.500
DigitsB1CompleteFacMiss
20110000.96837.994%
25500000.08791.625%
302500000.00599.463%


ECM Summary

B1B2factorcurvesGHz-days
500005000000272.318
50000500000030.258


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-03-26T00:00:00ANONYMOUSv4_computersC1A6FA8285630C8B0.148


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-28T13:09:25alpertronManual testing
5351755096757932603079543
4FB5B51B1D772B__no
2017-10-29T03:14:45Oliver KruseGTX-3
5351755096757932603079543
4FB5B51B1D772B__no


P-1 factor-bounds graph:
B1 = 589050, B2 = 5890500 (P-1 stage 2)
B1 = 589050 (P-1 stage 1)
B1 = 85000, B2 = 1636250 (P-1 stage 2)
B1 = 142046 (P-1 stage 1)
B1 = 113523 (P-1 stage 1)
B1 = 85000 (P-1 stage 1)
B1 = 75011 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
102
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105
106
102
103
104
105
106
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109
TF factor-bounds graph:
267
266
265
264
263
262
261
260
250
260
270
280
290
2100
Last modified: 2017-10-29T03:14:45+00:00