is 2 28409 - 1
has 8552 decimal digits
takes 0.000 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
-unknown- primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actualunknown500000000100000000000.812850.1529%0.812850.1529%50.1529%
PrimeNet2400.000062.5000%500100000.00004.0468%0.000064.0175%1.5175%
GPU722440.000165.9091%500100000.00001.7306%0.000166.4991%0.5900%
Difference-44-0.0001-65.9091%+499999500+9999990000+0.8128+48.4223%+0.8127-16.3461%-16.3461%

Known prime factors (2 factors, 126.5 bits, 0.44529145% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
28409909089619.79416
24
-16162.467e-121.278e-82.601e-8
2840913260046958849891998413014714410333106.7092333775732839926079484144939
3 × 7 × 73211026051 × 1517970499100309
2018-02-137321102605115179704991003095.741e+1266,111123,374

1 Composite Factors:
exponentprime factorscomposite factordigitsbits*
2840912054562829773889466945289133708545216739126.503
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2016-12-28T07:28:38kkmrkkblmbrbkManual testing5000000001000000000012-
skipped known factor: 909089
--0.813--42.827%


Trial Factoring results:
No TF results for M28409


ECM factoring results:

Old Calculation Method

Total ECM effort:19.207 GHz-days
Estimated T-Level:31.617
DigitsB1CurvesCompleteFacMiss
20110001283 / 10012.8300.000%
25500001283 / 2804.5821.015%
302500001119 / 6401.74817.381%
351000000511 / 15800.32372.360%
403000000500 / 47000.10689.907%

New Calculation Method

Total ECM effort:19.207 GHz-days
Estimated T-Level:31.617
DigitsB1CompleteFacMiss
2011000157.5280.000%
255000031.9270.000%
302500005.4990.409%
3510000000.79745.081%
4030000000.09890.623%
45110000000.01198.945%
50440000000.00199.899%


ECM Summary

B1B2factorcurvesGHz-days
5000050000001640.094
250000250000006081.747
1000000100000000110.126
300000030000000035612.27
30000003000000001444.965


Lucas-Lehmer results:
No L-L results for M28409


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-21T19:38:10Oliver KrusePRP
909089
21BA922BD99A3C__no
2017-09-21T21:28:57Oliver KruseManual testing
909089
21BA922BD99A3C__no
2017-10-12T16:30:08kkmrkkblmbrbkManual testing
909089
21BA922BD99A3C__no
2018-02-15T22:43:29Oliver KruseGTX-7
909089
132600469588498919984130147144103
94375CEC983AC8__no
2018-02-17T07:38:19Chang Chia-Tcheexbpc13
909089
132600469588498919984130147144103
94375CEC983AC8__no


P-1 factor-bounds graph:
B1 = 500000000, B2 = 10000000000 (P-1 stage 2)
B1 = 500000000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2018-02-17T07:38:19+00:00