is 2 1901857 - 1
has 572517 decimal digits
takes 0.103 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-LC4EA6676ED97ACE5double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26715.623668.6567 %500000150000000.10155.0921 %15.725170.2528 %
Target2610.161565.5738 %100008000000.00421.7277 %0.165766.1685 %
Difference+6+15.4621+3.0829 %+490000+14200000+0.0973+3.3645%+15.5594+4.0842 %

Known prime factors (2 factors, 141.2 bits, 0.00742181% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1901857123337907379854903212063.4193242565223880
23 × 5 × 41 × 151 × 13093867
2015-09-16151130938671.42010.05610.1048
19018572511753748258519984272732477.73366034243065028548
22 × 3 × 6287 × 875274946517
2009-07-27628787527494651726,2943,751.27,006.2

1 Composite Factors:
P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2002-08-03Jossv4_computers20000160000--0.0022.068%
2015-09-16alpertronManual testing500000150000001222063.4190.1018.901%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2002-01-02Jossv4_computers212580.020
2022-03-08LordJuliusManual testing21260
2009-05-24Architects Cubedi4l_12602610.081


ECM factoring results:
Total ECM effort:38.864 GHz-days
Estimated T-Level:25.692
DigitsB1CompleteFacMiss
201100015.1590.000%
25500001.67118.802%
302500000.13887.069%
3510000000.00999.073%


ECM Summary

B1B2factorcurvesGHz-days
10.103
500005000000312.097
50000660000022517.61
50000675000070.554
250000400000004318.50


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-12-27ANONYMOUSv4_computersC4EA6676ED97ACE50.103


PRP results:
dateuseridcompidcofactorsres64
2017-10-04Oliver KruseGTX-0
251175374825851998427273
12333790737985490321
9F69F4CD2FD978F1
2017-10-05Oliver KruseManual testing
251175374825851998427273
12333790737985490321
9F69F4CD2FD978F1
2017-11-15kkmrkkblmbrbkc4.xlarge
12333790737985490321
251175374825851998427273
9F69F4CD2FD978F1


CERT results:
No CERT results for M1901857


P-1 factor-bounds graph:
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
B1 = 20000, B2 = 160000 (P-1 stage 2)
B1 = 20000 (P-1 stage 1)
101
102
103
104
105
106
101
102
103
104
105
106
107
108
109
1010
1011
1012
TF factor-bounds graph:
261
260
258
this exponent TF target: 61
TF double-checked to: 67
ECM T-Level=25.69 ~= 69-bit
250
260
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280
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Last modified: 2024-03-13T02:15:48+00:00