is 2 6956251 - 1
has 2094041 decimal digits
takes 1.517 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LF1F5FA04703C9C65double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272137.478368.0556 %40000004568186709.06528.0822 %146.543570.6374 %
Target2674.271565.6716 %4500045000000.09102.2382 %4.362566.4400 %
Difference+5+133.2068+2.3839 %+3955000+452318670+8.9742+5.8439%+142.1810+4.1974 %

Known prime factors:
No known factors for M6956251

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2000-06-11ANONYMOUSv4_computers8500085000--0.0271.043%
2001-10-20ANONYMOUSv4_computers35000288750--0.0151.540%
2011-05-23Carsten Kossendeymother4450001335000012--0.3635.743%
2021-11-08Seth_TrManual testing20000005800000012--1.5978.434%
2021-12-04Seth_TrManual testing4000000456818670--10.8611.736%


Trial Factoring results:
57585960616263646566676869707172
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
1998-08-02ANONYMOUSv4_computers212620.044
2000-05-24Dave Zookv4_computers212630.141
2014-02-09NesowaManual testing2632640.282
2014-02-16lycornManual testing2642650.537
2015-06-26VictordeHollanderManual testing2652661.074
2016-04-06Gordon SpenceManual testing2662672.149
2018-02-27ANONYMOUSManual testing2672684.297
2020-05-01TJAOIManual testing2682698.594
2021-08-01takahashiManual testing26927017.19
2021-08-17SRBaseManual testing27027134.38
2021-09-25SRBaseManual testing27127268.75


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)
2000-07-25ANONYMOUSv4_computersF1F5FA04703C9C651.517
2002-07-20dswansonv4_computersF1F5FA04703C9C651.517


PRP results:
No PRP results for M6956251


CERT results:
No CERT results for M6956251


P-1 factor-bounds graph:
B1 = 4000000, B2 = 456818670 (P-1 stage 2)
B1 = 2000000, B2 = 58000000 (P-1 stage 2)
B1 = 4000000 (P-1 stage 1)
B1 = 2000000 (P-1 stage 1)
B1 = 445000, B2 = 13350000 (P-1 stage 2)
B1 = 445000 (P-1 stage 1)
B1 = 85000 (P-1 stage 1)
B1 = 35000, B2 = 288750 (P-1 stage 2)
B1 = 35000 (P-1 stage 1)
103
104
105
106
107
103
104
105
106
107
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109
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
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Last modified: 2024-03-13T02:15:48+00:00