is 2 2528809 - 1
has 761248 decimal digits
takes 0.175 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-L871F46203D65E281double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26711.750267.1642 %2880002905893901.61977.6560 %13.369869.6781 %
Target2630.631165.0794 %110009000000.00601.4348 %0.637165.5804 %
Difference+4+11.1190+2.0848 %+277000+289689390+1.6137+6.2211%+12.7327+4.0977 %

Known prime factors (1 factor, 67.2 bits, 0.00265844% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
25288091726941023159972218092167.22734145343186456
23 × 3 × 1422722632769
2013-10-048142272263276911.7507,795.814,560

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2011-01-06JossManual testing5000050000--0.0051.132%
2011-03-17James HeinrichWHS300000800000012--0.0726.524%
2023-01-28USAFSSUSAFSACS288000290589390--1.80410.888%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
1999-08-16ANONYMOUSv4_computers212590.015
2022-03-10LordJuliusManual testing21260
2009-01-31Sturle Sundegehry.ifi2602610.061
2012-06-14Sebastian HornbostelManual testing2612620.121
2013-01-14dbaughManual testing2622630.388


ECM factoring results:
Total ECM effort:0.698 GHz-days
Estimated T-Level:1.538
DigitsB1CompleteFacMiss
20110000.30873.514%
25500000.02897.193%
302500000.00299.821%


ECM Summary

B1B2factorcurvesGHz-days
10.092
50000500000080.606


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2019-05-06MadPooManual testing871F46203D65E2810.175


PRP results:
dateuseridcompidcofactorsres64
2017-10-15kkmrkkblmbrbkc4.xlarge
172694102315997221809
1DDF3C44AC1DAC80
2017-11-09Oliver KruseThreadripper-PC
172694102315997221809
1DDF3C44AC1DAC80


CERT results:
No CERT results for M2528809


P-1 factor-bounds graph:
B1 = 288000, B2 = 290589390 (P-1 stage 2)
B1 = 300000, B2 = 8000000 (P-1 stage 2)
B1 = 300000 (P-1 stage 1)
B1 = 288000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
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TF factor-bounds graph:
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this exponent TF target: 63
TF double-checked to: 67
ECM T-Level=1.54 ~= -11-bit
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Last modified: 2024-02-09T03:30:02+00:00