is 2 1872971 - 1
has 563821 decimal digits
takes 0.102 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LE2D07896BBFE18A5double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26715.864668.6567%500000150000000.10155.0828%15.966170.2498%1.5931%
PrimeNet2570.010363.1579%90001600000.00143.0300%0.011664.2742%1.1163%
GPU722610.164065.5738%100001500000.00141.6902%0.165466.1556%0.5819%
Difference+6+15.7006+3.0829%+490000+14850000+0.1001+3.3926%+15.8007+4.0942%+4.0942%

Known prime factors (1 factor, 80.0 bits, 0.00427037% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
187297111945242346354335959150972579.983318884871852109188
22 × 32 × 17 × 79 × 59407 × 111024233
2016-02-2959407111024233102,5520.48020.8887

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2012-01-10T21:25:00markrtiny2750006000000---0.046--3.929%
2015-10-07T11:10:18Bruno Victal5820K-linux5000001500000012---0.101--5.083%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2003-01-09T00:00:00ANONYMOUSv4_computers21258--0.021--
2010-04-11T14:32:00Architects CubedManual testing260261--0.082--
2016-02-23T16:28:56Mark RoseManual testing261262--0.164--
2011-03-08T05:15:00GrunwalderGIMPManual testing21263--0.852--
2016-02-23T16:28:56Mark RoseManual testing262263--0.524--
2015-05-08T22:25:00snme2pm1Manual testing263264--1.048--
2015-05-08T22:25:00snme2pm1Manual testing264265--1.995--
2015-09-11T08:33:00ramgeisManual testing265266--3.990--


ECM factoring results:

Old Calculation Method

Total ECM effort:19.854 GHz-days
Estimated T-Level:24.607
DigitsB1CurvesCompleteFacMiss
2011000258 / 1002.5807.480%
2550000258 / 2800.92139.729%

New Calculation Method

Total ECM effort:19.854 GHz-days
Estimated T-Level:24.607
DigitsB1CompleteFacMiss
20110008.8210.015%
25500000.79944.963%
302500000.04995.175%
3510000000.00299.773%


ECM Summary

B1B2factorcurvesGHz-days
500005000000312.147
50000500000030.208
50000660000021716.95
50000670000070.551


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-12-21T00:00:00ANONYMOUSv4_computersE2D07896BBFE18A50.102
2015-06-27T00:55:00MadPooManual testingE2D07896BBFE18A50.102


PRP results:
dateuseridcompidcofactorsres64PRP
2017-10-04T11:50:41Oliver KruseGTX-2
1194524234635433595915097
556CBD420A85EC__no
2017-11-07T16:46:59ATHec2-1xf
1194524234635433595915097
556CBD420A85EC__no


P-1 factor-bounds graph:
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 275000, B2 = 6000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
B1 = 275000 (P-1 stage 1)
103
104
105
106
103
104
105
106
107
108
109
TF factor-bounds graph:
267
266
265
264
263
262
261
258
250
260
270
280
290
2100
Last modified: 2021-10-07T10:31:17+00:00