is 2 1666843 - 1
has 501770 decimal digits
takes 0.078 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26717.826568.6567 %500000150000000.08805.0118 %17.914570.2276 %
Target2610.184365.5738 %70004000000.00191.2063 %0.186265.9890 %
Difference+6+17.6422+3.0829 %+493000+14600000+0.0861+3.8056%+17.7283+4.2385 %

Known prime factors (3 factors, 185.4 bits, 0.01112072% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1666843140596873575611443.6774217460
22 × 3 × 5 × 13 × 5407
-1354071.315e-62.094e-53.752e-5
16668432687413733900153767372167.86580613883068176
24 × 5038367691761
2019-12-0916503836769176135.74418,73234,987
1666843167142817768401190305432373.8235013754077870597
3 × 28072339 × 59533741
2019-03-0928072339595337411,430.02.03263.8987

4 Composite Factors:
P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2016-03-17alpertronManual testing5000001500000012
skipped known factor: 14059687357561
---8.776%


Trial Factoring results:
5758596061626364656667
No TF results for M1666843


ECM factoring results:
Total ECM effort:38.230 GHz-days
Estimated T-Level:25.718
DigitsB1CompleteFacMiss
201100014.6540.000%
25500001.67418.740%
302500000.14486.623%
3510000000.01099.005%


ECM Summary

B1B2factorcurvesGHz-days
50000500000024016.38
50000500000090.615
50000500000020.119
250000400000005021.11


Lucas-Lehmer results:
No L-L results for M1666843


PRP results:
dateuseridcompidcofactorsres64
2017-10-02Oliver KruseGTX-2
14059687357561
67214C8080ED1789
2017-11-02ATHec2-1xh
14059687357561
67214C8080ED1789
2019-03-10_p95holder_TFL17_PRPt15-E_g
14059687357561
16714281776840119030543
4389FE82243E772C
2019-03-12RuzovejMasa_notebook
14059687357561
16714281776840119030543
4389FE82243E772C
2019-12-11mnd975201
14059687357561
268741373390015376737
16714281776840119030543
4389FE82243E772C
2019-12-12ANONYMOUS
14059687357561
268741373390015376737
16714281776840119030543
4389FE82243E772C


CERT results:
No CERT results for M1666843


P-1 factor-bounds graph:
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
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TF factor-bounds graph:
this exponent TF target: 61
TF double-checked to: 67
ECM T-Level=25.72 ~= 69-bit
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Last modified: 2024-03-13T02:15:48+00:00