is 2 845921 - 1
has 254648 decimal digits
takes 0.021 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-LE7186A387159BEA6double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26735.126170.1493 %100000003000000000.90729.7857 %36.033373.0703 %
Target2440.000054.5455 %1400027500000.005717.5596 %0.005762.5271 %
Difference+23+35.1261+15.6038 %+9986000+297250000+0.9015-7.7739 %+36.0276+10.5433 %

Known prime factors (1 factor, 69.6 bits, 0.00823215% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
8459219182962111066383940572169.638542778942186468
22 × 33 × 13 × 386594688167
2014-03-1527386594688167141.13740.621,383.3

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2002-01-08ANONYMOUSv4_computers2000200000--0.00012.027%
2002-02-10ANONYMOUSv4_computers4096409600--0.00114.944%
2002-04-07ANONYMOUSv4_computers8192819200--0.00217.737%
2002-05-18ANONYMOUSv4_computers163841638400--0.00420.494%
2002-06-15ANONYMOUSv4_computers32768327680012--0.00723.207%
2002-12-09ANONYMOUSv4_computers65537655370012--0.01525.869%
2003-08-08ANONYMOUSv4_computers1310721310720012--0.02928.473%
2009-08-29Carsten Kossendeymother845921845921--0.03019.917%
2012-03-20JossManual testing12381561238156--0.04421.092%
2012-08-07markrManual testing1000000030000000012--0.90739.539%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2000-08-10ANONYMOUSv4_computers212550.006
2001-01-14ANONYMOUSv4_computers212560.011
2001-11-24ANONYMOUSv4_computers212570.023
2003-09-09ANONYMOUSv4_computers212580.045
2008-10-11Sturle Sundeaalto.ifi2582590.045
2008-10-11Sturle Sundeaalto.ifi2592600.091
2010-05-22Architects Cubeda3_bu22602610.182
2012-10-15Richard B. WoodsPuttputt2612620.363


ECM factoring results:
Total ECM effort:13.855 GHz-days
Estimated T-Level:25.655
DigitsB1CompleteFacMiss
201100014.7310.000%
25500001.61319.937%
302500000.13187.717%
3510000000.00999.131%


ECM Summary

B1B2factorcurvesGHz-days
10.056
5000050000002797.662
25000025000000446.137


Lucas-Lehmer results:
No L-L results for M845921


PRP results:
dateuseridcompidcofactorsres64
2017-09-28Oliver KruseGTX-2
918296211106638394057
DEF197A535AC9F7C
2017-10-14Oliver KruseGTX-2
918296211106638394057
DEF197A535AC9F7C
2017-12-18ATHxps
918296211106638394057
DEF197A535AC9F7C
2020-04-22Oliver KruseAddPrpType5
918296211106638394057
DDA0BF2F2373DCB1


CERT results:
No CERT results for M845921


P-1 factor-bounds graph:
B1 = 10000000, B2 = 300000000 (P-1 stage 2)
B1 = 10000000 (P-1 stage 1)
B1 = 1238156 (P-1 stage 1)
B1 = 845921 (P-1 stage 1)
B1 = 131072, B2 = 13107200 (P-1 stage 2)
B1 = 65537, B2 = 6553700 (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 = 65537 (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)
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1010
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TF factor-bounds graph:
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261
260
259
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255
this exponent TF target: 44
TF double-checked to: 67
ECM T-Level=25.66 ~= 69-bit
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Last modified: 2024-03-03T02:29:32+00:00