is 2 687847 - 1
has 207063 decimal digits
takes 0.014 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-LE584C92E3403ED09double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26743.198470.1493 %131072131072000.02433.5155 %43.222771.1987 %
Target2440.000054.5455 %1100020000000.003516.0639 %0.003561.8472 %
Difference+23+43.1984+15.6038 %+120072+11107200+0.0208-12.5484 %+43.2192+9.3514 %

Known prime factors (1 factor, 79.6 bits, 0.01157549% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
6878479300582444952590201205132479.622676064767670178848
25 × 13 × 2377 × 18617 × 36724517
2008-04-131861736724517177,9950.05850.1082

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2002-01-02ANONYMOUSv4_computers2000200000--0.00011.648%
2002-01-28ANONYMOUSv4_computers4096409600--0.00114.546%
2002-03-16ANONYMOUSv4_computers8192819200--0.00217.325%
2002-05-05ANONYMOUSv4_computers163841638400--0.00320.071%
2002-07-14ANONYMOUSv4_computers32768327680012--0.00622.776%
2002-10-19ANONYMOUSv4_computers65536655360012--0.01225.431%
2003-06-30ANONYMOUSv4_computers1310721310720012--0.02428.031%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2000-02-16ANONYMOUSv4_computers2532540.002
2022-03-07LordJuliusManual testing254255
2001-04-01ANONYMOUSv4_computers212560.014
2001-12-22ANONYMOUSv4_computers212570.028
2003-10-08ANONYMOUSv4_computers212580.056


ECM factoring results:
Total ECM effort:11.265 GHz-days
Estimated T-Level:25.655
DigitsB1CompleteFacMiss
201100014.7310.000%
25500001.61319.937%
302500000.13187.717%
3510000000.00999.131%


ECM Summary

B1B2factorcurvesGHz-days
10.038
5000050000002796.272
25000025000000444.954


Lucas-Lehmer results:
No L-L results for M687847


PRP results:
dateuseridcompidcofactorsres64
2017-09-27Oliver KruseGTX-2
930058244495259020120513
93A58AD3157F0564
2017-09-28Oliver KruseManual testing
930058244495259020120513
93A58AD3157F0564
2017-11-09kkmrkkblmbrbkc4.large
930058244495259020120513
93A58AD3157F0564
2020-04-20Oliver KruseAddPrpType5
930058244495259020120513
CF766781B9B86FE0


CERT results:
No CERT results for M687847


P-1 factor-bounds graph:
B1 = 131072, B2 = 13107200 (P-1 stage 2)
B1 = 65536, B2 = 6553600 (P-1 stage 2)
B1 = 32768, B2 = 3276800 (P-1 stage 2)
B1 = 131072 (P-1 stage 1)
B1 = 16384, B2 = 1638400 (P-1 stage 2)
B1 = 65536 (P-1 stage 1)
B1 = 8192, B2 = 819200 (P-1 stage 2)
B1 = 32768 (P-1 stage 1)
B1 = 4096, B2 = 409600 (P-1 stage 2)
B1 = 16384 (P-1 stage 1)
B1 = 2000, B2 = 200000 (P-1 stage 2)
B1 = 8192 (P-1 stage 1)
B1 = 4096 (P-1 stage 1)
B1 = 2000 (P-1 stage 1)
102
103
104
105
106
102
103
104
105
106
107
108
TF factor-bounds graph:
258
257
256
255
254
this exponent TF target: 44
TF double-checked to: 67
ECM T-Level=25.66 ~= 69-bit
250
260
270
280
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Last modified: 2024-02-09T03:30:02+00:00