is 2 25661081 - 1
has 7724756 decimal digits
takes 21.990 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LAA5B2B901F6D921Edouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual27118.630564.7887%28000035000000.56593.2541%19.196465.9345%1.1458%
PrimeNet2660.575562.1212%12000045000000.44565.1739%1.021164.0810%1.9598%
GPU722709.311864.2857%18000055000000.58383.7458%9.895665.6235%1.3378%
Difference+1+9.3187+0.5030%+100000-2000000-0.0179-0.4917%+9.3008+0.3110%+0.3110%

Known prime factors (1 factor, 67.6 bits, 0.00026340% known):
Remaining cofactor is PRP status unknown

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
256610812223881507416958393592167.5924333179703959
32 × 481464411551
2011-10-1194814644115512.135932,59460,877

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2004-09-16T00:00:00ANONYMOUSv4_computers2800003500000---0.566--3.254%
2011-10-11T05:18:00Carsten KossendeyManual testing28000035000002167.5920.56643.981.1323.254%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2001-08-12T00:00:00Net_Forcev4_computers21256--0.000--
2004-04-29T00:00:00ANONYMOUSv4_computers21262--0.024--
2004-06-04T00:00:00Team Prime Ribv4_computers21267--1.158--
2011-10-11T05:18:00Carsten KossendeyManual testing267271--17.47--


ECM factoring results:
No ECM results for M25661081


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2004-10-18T00:00:00ANONYMOUSv4_computersAA5B2B901F6D921E21.99


PRP results:
No PRP results for M25661081


P-1 factor-bounds graph:
B1 = 280000, B2 = 3500000 (P-1 stage 2)
B1 = 280000 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2011-10-11T05:18:52+00:00