is 2 74207281 - 1
has 22338618 decimal digits
takes 205.161 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
Verified Mersenne Prime

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual275103.115364.0000 %640000126400005.18663.6504 %108.301965.3142 %
Target27451.556563.5135 %5000008500000020.46024.1329 %72.016665.0215 %
Difference+1+51.5589+0.4865 %+140000-72360000-15.2736-0.4825 %+36.2853+0.2927 %

Known prime factors:
None — M74207281 is prime!

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2015-06-14TheJudgerManual testing640000126400006--5.2894.023%


Trial Factoring results:
57585960616263646566676869707172737475
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2024-01-29Morgan SteelbelowAverageLaptop?263
2008-09-12lycornManual testing212640.025
2024-01-29Morgan SteelbelowAverageLaptop263264
2010-08-25PalantsevichOffice552642650.050
2010-08-27fswebfs75broad22652660.101
2010-08-31ANONYMOUSdownstairs2662670.201
2010-09-01GrunwalderGIMPcompute-0-32672680.403
2011-01-04SADMASTERManual testing2682690.806
2016-10-14SADMASTERManual testing268269
2012-10-23Clown_RoyalManual testing2692701.611
2013-05-10SMoffatManual testing2702713.222
2015-06-07kdgehmanManual testing2712726.445
2015-06-07kdgehmanManual testing27227312.89
2015-06-07kdgehmanManual testing27327425.78
2015-06-07kdgehmanManual testing27427551.56


ECM factoring results:
No ECM results for M74207281


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2015-09-17curtisccsc143-05l0000000000000000209.0


PRP results:
No PRP results for M74207281


CERT results:
No CERT results for M74207281


P-1 factor-bounds graph:
B1 = 640000, B2 = 12640000 (P-1 stage 2)
B1 = 640000 (P-1 stage 1)
104
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108
TF factor-bounds graph:
275
274
273
272
271
270
269
268
267
266
265
264
263
this exponent TF target: 74
TF double-checked to: 67
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Last modified: 2024-03-13T02:15:48+00:00