is 2 1851901 - 1
has 557478 decimal digits
takes 0.100 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-L60CF3345A556B228double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26832.185869.1176 %18519012037091101.01088.1500 %33.196671.6346 %
Target2610.165965.5738 %90007500000.00391.6313 %0.169866.1354 %
Difference+7+32.0199+3.5439 %+1842901+202959110+1.0069+6.5187%+33.0268+5.4992 %

Known prime factors (1 factor, 82.6 bits, 0.00445997% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
185190172998453342353241830810632582.5941970905932400091631
3 × 7 × 31 × 27878651 × 108595831
2019-12-2527878651108595831528,8982.53894.4631

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2012-01-04markrtiny275000600000012--0.0467.172%
2015-10-07Bruno Victal5820K.ECM5000001500000012--0.1018.876%
2016-10-29JossManual testing864000864000---4.731%
2016-12-18JossManual testing720000720000---4.459%
2017-01-11JossManual testing10368001036800---5.010%
2017-02-11JossManual testing12441601244160012--0.1469.115%
2018-01-12JossManual testing18519011244160012--0.1919.265%
2018-02-04JossManual testing18519012488320012--0.24410.448%
2018-02-10JossManual testing18519014976640012--0.35111.616%
2018-02-24JossManual testing18519019953280012--0.56412.769%
2018-09-24JossManual testing185190118519010012--0.93113.789%
2018-10-25JossManual testing185190120370911012--1.01113.944%


Trial Factoring results:
575859606162636465666768
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2003-01-16ANONYMOUSv4_computers212580.021
2016-02-23Mark RoseManual testing2582600.062
2010-04-13Architects Cubeda3_bu22602610.083
2016-02-23Mark RoseManual testing2612620.530
2011-01-21GrunwalderGIMPManual testing212630.862
2016-02-23Mark RoseManual testing2622630.166
2015-05-01snme2pm1Manual testing2632641.060
2015-05-01snme2pm1Manual testing2642652.018
2015-09-08ramgeisManual testing2652664.035
2018-06-11TJAOIManual testing2662678.070
2019-06-10TJAOIManual testing26726816.14


ECM factoring results:
Total ECM effort:39.377 GHz-days
Estimated T-Level:25.717
DigitsB1CompleteFacMiss
201100015.0180.000%
25500001.69118.429%
302500000.14386.637%
3510000000.01099.017%


ECM Summary

B1B2factorcurvesGHz-days
500005000000724.874
50000500000030.207
50000660000017613.73
250000400000004820.57


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-12-27Stephen Woodv4_computers60CF3345A556B2280.100
2015-07-03MadPooManual testing60CF3345A556B2280.100


PRP results:
dateuseridcompidcofactorsres64
2019-12-26Niels_Mache_NextcloudSuperDry-X
7299845334235324183081063
5DA69D60B5BA042A
2019-12-26marssystemssystem11
7299845334235324183081063
5DA69D60B5BA042A


CERT results:
No CERT results for M1851901


P-1 factor-bounds graph:
B1 = 1851901, B2 = 203709110 (P-1 stage 2)
B1 = 1851901, B2 = 185190100 (P-1 stage 2)
B1 = 1851901, B2 = 99532800 (P-1 stage 2)
B1 = 1851901, B2 = 49766400 (P-1 stage 2)
B1 = 1851901, B2 = 24883200 (P-1 stage 2)
B1 = 1851901, B2 = 12441600 (P-1 stage 2)
B1 = 1244160, B2 = 12441600 (P-1 stage 2)
B1 = 1851901 (P-1 stage 1)
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 1244160 (P-1 stage 1)
B1 = 1036800 (P-1 stage 1)
B1 = 864000 (P-1 stage 1)
B1 = 720000 (P-1 stage 1)
B1 = 275000, B2 = 6000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
B1 = 275000 (P-1 stage 1)
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109
TF factor-bounds graph:
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266
265
264
263
262
261
260
258
this exponent TF target: 61
TF double-checked to: 67
ECM T-Level=25.72 ~= 69-bit
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Last modified: 2024-02-29T14:28:04+00:00