is 2 2787497 - 1
has 839121 decimal digits
takes 0.215 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LF75B039BC177D0B0double-checked
PRP3D40E89F971471ADverified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26821.382967.6471%3000000900000000.86687.8332%22.249870.1813%2.5343%
PrimeNet2590.027562.7119%120002200000.00262.8595%0.030263.7781%1.0662%
GPU722630.572665.0794%150002400000.00311.7484%0.575665.6899%0.6105%
Difference+5+20.8104+2.5677%+2985000+89760000+0.8638+6.0848%+21.6741+4.4914%+4.4914%

Known prime factors (1 factor, 84.4 bits, 0.00302684% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2787497250527485327361219045495372684.3734493771389303041744
24 × 32 × 1217 × 1459 × 17575294567
2021-03-011459175752945671,796,138107.24200.29

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-28T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.242%
2010-11-11T11:52:00Jocelyn LaroucheManual testing1500015000---0.002--0.211%
2010-11-24T12:14:00markrtiny1000002075000---0.023--2.483%
2014-11-01T00:51:00Jocelyn LaroucheManual testing123026123026---0.014--0.946%
2016-05-04T08:48:52Jocelyn LaroucheManual testing20000036000006---0.043--3.183%
2017-07-20T22:03:21Jocelyn Larouchelow 4M40000040000006---0.067--3.575%
2019-11-11T20:36:09BigBrotherWinston30000009000000012---0.867--7.833%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2016-02-23T16:29:21Mark RoseManual testing21260--0.055--
2009-01-30T19:16:00Sturle Sundeinteravia.ifi260261--0.055--
2012-03-07T17:51:00markroldgamer261262--0.110--
2013-01-10T10:21:00dbaughManual testing262263--0.352--
2015-04-21T09:20:00VictordeHollanderManual testing263264--0.704--
2015-04-21T09:20:00VictordeHollanderManual testing264265--1.340--
2016-02-08T11:13:53ramgeisManual testing265266--2.681--
2017-10-19T22:32:32Gordon SpenceManual testing266267--5.362--
2019-02-26T02:05:07chuenkitManual testing267268--10.72--


ECM factoring results:

Old Calculation Method

Total ECM effort:7.808 GHz-days
Estimated T-Level:3.750
DigitsB1CurvesCompleteFacMiss
201100075 / 1000.75047.059%
255000075 / 2800.26876.465%

New Calculation Method

Total ECM effort:7.808 GHz-days
Estimated T-Level:3.750
DigitsB1CompleteFacMiss
20110002.4198.898%
25500000.21980.360%
302500000.01398.663%


ECM Summary

B1B2factorcurvesGHz-days
500005000000747.704
50000500000010.104


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-07-04T00:00:00ANONYMOUSv4_computersF75B039BC177D0B00.215
2018-08-27T22:28:07kkmrkkblmbrbkoldF75B039BC177D0B00.215


PRP results:
dateuseridcompidcofactorsres64PRP
2021-03-02T11:27:09Krieselmartin
25052748532736121904549537
3D40E89F971471ADno


P-1 factor-bounds graph:
B1 = 3000000, B2 = 90000000 (P-1 stage 2)
B1 = 3000000 (P-1 stage 1)
B1 = 400000, B2 = 4000000 (P-1 stage 2)
B1 = 400000 (P-1 stage 1)
B1 = 200000, B2 = 3600000 (P-1 stage 2)
B1 = 100000, B2 = 2075000 (P-1 stage 2)
B1 = 200000 (P-1 stage 1)
B1 = 123026 (P-1 stage 1)
B1 = 100000 (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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TF factor-bounds graph:
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265
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2100
Last modified: 2021-03-02T11:27:09+00:00