is 2 6921727 - 1
has 2083648 decimal digits
takes 1.509 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L06A38201ED3555B3double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272138.164068.0556 %35000009616446840166.703011.2945 %304.867071.6635 %
Target2674.292865.6716 %4500045000000.09102.2364 %4.383866.4394 %
Difference+5+133.8712+2.3839 %+3455000+9611946840+166.6120+9.0581%+300.4832+5.2242 %

Known prime factors:
No known factors for M6921727

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2001-12-01ANONYMOUSv4_computers35000341250--0.0161.619%
2011-11-23James Heinrichi7-92013000028275006--0.0883.576%
2020-01-13takahashivaio6000001200000012--0.3865.804%
2021-06-02Dylan DelgadoManual testing7200002160000012--0.5466.574%
2023-07-18ThaZ-17035000009616446840--199.615.793%


Trial Factoring results:
57585960616263646566676869707172
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
1998-10-11ANONYMOUSv4_computers212620.044
2005-02-12David Campeauv4_computers212630.142
2014-02-09NesowaManual testing2632640.284
2014-02-17lycornManual testing2642650.540
2015-06-26VictordeHollanderManual testing2652661.080
2016-04-02Gordon SpenceManual testing2662672.159
2018-02-27ANONYMOUSManual testing2672684.318
2020-01-03mnd9Manual testing2682698.637
2021-07-18takahashiManual testing26927017.27
2021-08-12SRBaseManual testing27027134.55
2021-09-28SRBaseManual testing27127269.09


ECM factoring results:
Total ECM effort:1.989 GHz-days
Estimated T-Level:1.154
DigitsB1CompleteFacMiss
20110000.23179.392%
25500000.02197.887%
302500000.00199.865%


ECM Summary

B1B2factorcurvesGHz-days
50000500000061.989


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-03-15ANONYMOUSv4_computers06A38201ED3555B31.509
2002-02-03ANONYMOUSv4_computers06A38201ED3555B31.509
2015-05-03MadPooManual testing06A38201ED3555B31.509


PRP results:
No PRP results for M6921727


CERT results:
No CERT results for M6921727


P-1 factor-bounds graph:
B1 = 3500000, B2 = 9616446840 (P-1 stage 2)
B1 = 3500000 (P-1 stage 1)
B1 = 720000, B2 = 21600000 (P-1 stage 2)
B1 = 600000, B2 = 12000000 (P-1 stage 2)
B1 = 720000 (P-1 stage 1)
B1 = 600000 (P-1 stage 1)
B1 = 130000, B2 = 2827500 (P-1 stage 2)
B1 = 130000 (P-1 stage 1)
B1 = 35000, B2 = 341250 (P-1 stage 2)
B1 = 35000 (P-1 stage 1)
103
104
105
106
107
103
104
105
106
107
108
109
1010
TF factor-bounds graph:
272
271
270
269
268
267
266
265
264
263
262
this exponent TF target: 67
TF double-checked to: 67
ECM T-Level=1.15 ~= -13-bit
250
260
270
280
JSON version of this page
Last modified: 2024-03-13T02:15:48+00:00