is 2 20204221 - 1
has 6082077 decimal digits
takes 14.318 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-LE6B6318E805A8217double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual27011.826864.2857 %430000138675001.19424.9071 %13.020966.0382 %
Target2695.909063.7681 %150000200000001.26553.6730 %7.174565.0989 %
Difference+1+5.9178+0.5176 %+280000-6132500-0.0713+1.2341%+5.8465+0.9394 %

Known prime factors (1 factor, 87.0 bits, 0.00043039% known):
Remaining cofactor is PRP status unknown

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
202042211500973719061967453798039592786.9563714505298328422199
3 × 7 × 23 × 15131 × 161461 × 3147883
2021-01-0116146131478831,406,7530.33310.3377

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2003-08-08Grey Smithv4_computers305000305000--0.3131.830%
2021-01-01Dylan DelgadoManual testing430000138675001222786.9561.2295.403%


Trial Factoring results:
5758596061626364656667686970
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2002-07-27Net_Forcev4_computers212590.002
2002-08-31ANONYMOUSv4_computers212660.370
2015-02-11NRManual testing2662670.740
2017-04-28ramgeisManual testing2672681.479
2017-11-05VictordeHollanderManual testing2682692.959
2018-02-16ramgeisManual testing2692705.918


ECM factoring results:
No ECM results for M20204221


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2004-02-23ANONYMOUSv4_computersE6B6318E805A821714.32
2008-04-24ANONYMOUSv4_computersE6B6318E805A821714.32


PRP results:
No PRP results for M20204221


CERT results:
No CERT results for M20204221


P-1 factor-bounds graph:
B1 = 430000, B2 = 13867500 (P-1 stage 2)
B1 = 430000 (P-1 stage 1)
B1 = 305000 (P-1 stage 1)
104
105
106
104
105
106
107
108
TF factor-bounds graph:
270
269
268
267
266
259
this exponent TF target: 69
TF double-checked to: 67
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270
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290
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Last modified: 2024-03-13T02:15:48+00:00