is 2 2238647 - 1
has 673900 decimal digits
takes 0.147 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-L0FB865D4D75F1F78double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26713.273267.1642 %500000150000000.12305.1929 %13.396168.8693 %
Target2620.274464.5161 %110009500000.00591.6583 %0.280465.1046 %
Difference+5+12.9987+2.6481 %+489000+14050000+0.1171+3.5346%+13.1158+3.7648 %

Known prime factors (1 factor, 82.6 bits, 0.00368767% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
223864770990941820847815582291272582.5541585576953866505429
35 × 8849 × 315751 × 2335297
2015-12-023157512335297437,5260.04060.0613

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2003-03-27ANONYMOUSv4_computers204820480012--0.0010.783%
2010-11-08Oscar Östlin7501175011--0.0071.596%
2011-01-14Oscar Östlin8500016362506--0.0164.428%
2014-06-01JossManual testing113671113671--0.0111.964%
2014-09-30JossManual testing142342142342--0.0142.180%
2015-12-02Alexander DubrovinManual testing10000006000000622582.5540.1217.325%
2016-04-22alpertronManual testing5000001500000012
skipped known factor: 7099094182084781558229127
---8.287%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
1999-02-07ANONYMOUSv4_computers212580.017
2022-03-09LordJuliusManual testing21260
2009-01-11Sturle Sundegoscha.ifi2602610.069
2012-04-27Sebastian HornbostelManual testing2612620.137
2013-01-23dbaughManual testing2622630.439
2015-03-10VictordeHollanderManual testing2632640.877
2015-03-10VictordeHollanderManual testing2642651.669
2015-10-25ramgeisManual testing2652663.338


ECM factoring results:
Total ECM effort:17.188 GHz-days
Estimated T-Level:21.780
DigitsB1CompleteFacMiss
20110003.7192.427%
25500000.35670.041%
302500000.02397.734%
3510000000.00199.890%


ECM Summary

B1B2factorcurvesGHz-days
500005000000151.147
50000715000070.707
500002702353571.786
50000311301905013.55


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-07-12ANONYMOUSv4_computers0FB865D4D75F1F780.147


PRP results:
dateuseridcompidcofactorsres64
2017-09-30alpertronManual testing
7099094182084781558229127
69BA03668C375C8F
2017-10-28Oliver KruseGTX-0
7099094182084781558229127
69BA03668C375C8F


CERT results:
No CERT results for M2238647


P-1 factor-bounds graph:
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 1000000, B2 = 6000000 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
B1 = 500000 (P-1 stage 1)
B1 = 85000, B2 = 1636250 (P-1 stage 2)
B1 = 142342 (P-1 stage 1)
B1 = 113671 (P-1 stage 1)
B1 = 85000 (P-1 stage 1)
B1 = 75011 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
102
103
104
105
106
102
103
104
105
106
107
108
TF factor-bounds graph:
266
265
264
263
262
261
260
258
this exponent TF target: 62
TF double-checked to: 67
ECM T-Level=21.78 ~= 56-bit
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Last modified: 2024-02-29T14:28:04+00:00