is 2 1905121 - 1
has 573499 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-L9A80A5BF857858F5double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26715.596968.6567 %1000000300000000.20296.2197 %15.799870.6062 %
Target2610.161265.5738 %100008000000.00421.7283 %0.165466.1687 %
Difference+6+15.4356+3.0829 %+990000+29200000+0.1988+4.4914%+15.6344+4.4374 %

Known prime factors (1 factor, 68.7 bits, 0.00360385% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
19051214656132356824102593132168.658122200436529336
23 × 3 × 11 × 29 × 359 × 44460709
2015-07-163594446070931.2870.19060.3559

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2011-06-02kurlyslice10000003000000012--0.20310.437%
2016-03-16alpertronManual testing5000001500000012---8.903%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2011-02-05GrunwalderGIMPv4_computers212560.005
2011-02-05GrunwalderGIMPv4_computers2562570.005
2002-01-02Jossv4_computers212580.020
2011-02-05GrunwalderGIMPv4_computers2572580.010
2011-02-05GrunwalderGIMPv4_computers2582590.020
2011-02-05GrunwalderGIMPv4_computers2592600.040
2009-05-24Architects Cubedm1_tt2602610.081
2011-02-05GrunwalderGIMPv4_computers2602610.081
2011-02-05GrunwalderGIMPGWPrime022612620.161
2011-02-05GrunwalderGIMPGWPrime022622630.515
2015-05-17omylistManual testing2632641.031
2015-05-19omylistManual testing2642651.961


ECM factoring results:
Total ECM effort:39.133 GHz-days
Estimated T-Level:25.701
DigitsB1CompleteFacMiss
201100015.0520.000%
25500001.67518.738%
302500000.14086.919%
3510000000.01099.052%


ECM Summary

B1B2factorcurvesGHz-days
10.139
500005000000322.113
50000605902470.527
50000660000021716.99
250000400000004519.37


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-01-02ANONYMOUSv4_computers9A80A5BF857858F50.103
2015-06-29MadPooManual testing9A80A5BF857858F50.103


PRP results:
dateuseridcompidcofactorsres64
2017-10-04Oliver KruseGTX-2
465613235682410259313
9E116B4691F39B08
2017-11-09kkmrkkblmbrbkc4.large
465613235682410259313
9E116B4691F39B08


CERT results:
No CERT results for M1905121


P-1 factor-bounds graph:
B1 = 1000000, B2 = 30000000 (P-1 stage 2)
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
B1 = 500000 (P-1 stage 1)
101
102
103
104
105
106
101
102
103
104
105
106
107
108
TF factor-bounds graph:
265
264
263
262
261
260
259
258
257
256
this exponent TF target: 61
TF double-checked to: 67
ECM T-Level=25.7 ~= 69-bit
250
260
270
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Last modified: 2024-02-29T14:28:04+00:00