is 2 2805703 - 1
has 844601 decimal digits
takes 0.217 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-LA1791861093382DCdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26821.244267.6471 %65000006695000004.773310.9423 %26.017571.1872 %
Target2630.568865.0794 %1500013000000.00951.7904 %0.578465.7046 %
Difference+5+20.6753+2.5677 %+6485000+668200000+4.7638+9.1518%+25.4392+5.4826 %

Known prime factors (1 factor, 78.9 bits, 0.00281350% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
28057035792573389486639257392092478.939103228556078220668
22 × 25807139019555167
2021-04-0442580713901955516721,819157,466,201294,103,013

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2003-11-28ANONYMOUSv4_computers2048204800--0.0010.682%
2010-11-12JossManual testing1500015000--0.0020.515%
2010-12-19markrtiny10000021000006--0.0264.420%
2014-11-12JossManual testing122876122876--0.0151.857%
2015-01-26JossManual testing148679148679--0.0182.032%
2015-01-31JossManual testing179900179900--0.0222.215%
2015-02-01JossManual testing197890197890--0.0242.310%
2015-02-04JossManual testing435358435358--0.0543.180%
2015-02-25JossManual testing478893478893--0.0593.295%
2015-03-02JossManual testing526782526782--0.0653.412%
2015-03-12JossManual testing579460579460--0.0723.532%
2015-03-14JossManual testing637406637406--0.0793.653%
2015-03-29JossManual testing771260771260--0.0953.902%
2015-04-08JossManual testing848386848386--0.1054.030%
2015-05-01JossManual testing10265461026546--0.1274.291%
2015-05-07JossManual testing11292001129200--0.1394.425%
2015-05-22JossManual testing12421201242120--0.1534.561%
2015-06-08JossManual testing13663321366332--0.1694.698%
2015-06-25JossManual testing15029651502965--0.1854.838%
2015-07-07JossManual testing16532611653261--0.2044.980%
2016-05-08NumberwangStrand15000135000--0.0031.471%
2016-08-04JossManual testing165326133065226--0.2156.068%
2018-04-26JossManual testing280570356114066--0.3656.964%
2019-11-13masserManual testing30000003000000012--0.5529.766%
2020-01-04masserManual testing500000020000000012--1.92813.163%
2021-09-23Dylan Delgadolaptop-ryzen737006500000669500000--4.65215.345%


Trial Factoring results:
575859606162636465666768
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2016-02-23Mark RoseManual testing212600.055
2009-02-14Sturle Sundevancraft.ifi2602610.055
2012-02-27markroldgamer2612620.109
2013-01-10dbaughManual testing2622630.350
2015-04-21VictordeHollanderManual testing2632640.700
2015-04-21VictordeHollanderManual testing2642651.332
2016-02-10ramgeisManual testing2652662.663
2017-10-24Gordon SpenceManual testing2662675.327
2018-12-30chuenkitManual testing26726810.65


ECM factoring results:
Total ECM effort:8.594 GHz-days
Estimated T-Level:21.495
DigitsB1CompleteFacMiss
20110003.2313.953%
25500000.29974.161%
302500000.01998.132%


ECM Summary

B1B2factorcurvesGHz-days
500005000000798.073
50000500000050.521


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-05-30MikeGovev4_computersA1791861093382DC0.217
2018-09-02kkmrkkblmbrbkoldA1791861093382DC0.211


PRP results:
dateuseridcompidcofactorsres64
2021-04-05XZTM900Tiny4
579257338948663925739209
BAAB628A8EFBD66C


CERT results:
dateuseridcompid
2021-04-05Ben Deloi-0869cf814f59d2774


P-1 factor-bounds graph:
B1 = 6500000, B2 = 669500000 (P-1 stage 2)
B1 = 5000000, B2 = 200000000 (P-1 stage 2)
B1 = 6500000 (P-1 stage 1)
B1 = 5000000 (P-1 stage 1)
B1 = 3000000, B2 = 30000000 (P-1 stage 2)
B1 = 3000000 (P-1 stage 1)
B1 = 2805703, B2 = 5611406 (P-1 stage 2)
B1 = 2805703 (P-1 stage 1)
B1 = 1653261, B2 = 3306522 (P-1 stage 2)
B1 = 1653261 (P-1 stage 1)
B1 = 1502965 (P-1 stage 1)
B1 = 1366332 (P-1 stage 1)
B1 = 1242120 (P-1 stage 1)
B1 = 1129200 (P-1 stage 1)
B1 = 1026546 (P-1 stage 1)
B1 = 848386 (P-1 stage 1)
B1 = 771260 (P-1 stage 1)
B1 = 637406 (P-1 stage 1)
B1 = 579460 (P-1 stage 1)
B1 = 526782 (P-1 stage 1)
B1 = 478893 (P-1 stage 1)
B1 = 435358 (P-1 stage 1)
B1 = 100000, B2 = 2100000 (P-1 stage 2)
B1 = 197890 (P-1 stage 1)
B1 = 179900 (P-1 stage 1)
B1 = 148679 (P-1 stage 1)
B1 = 122876 (P-1 stage 1)
B1 = 100000 (P-1 stage 1)
B1 = 15000, B2 = 135000 (P-1 stage 2)
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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this exponent TF target: 63
TF double-checked to: 67
ECM T-Level=21.49 ~= 55-bit
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Last modified: 2024-02-09T03:30:02+00:00