is 2 251971 - 1
has 75851 decimal digits
takes 0.001 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L1D71AE7FD8244622double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual270948.325974.2857%100000000020289610196856089,947.026027.9387%90,895.352081.4699%7.1842%
PrimeNet2400.000055.0000%2600700000.000114.2215%0.000161.3997%6.3997%
GPU722440.000059.0909%45001100000.000110.1725%0.000163.2524%4.1615%
Difference+26+948.3259+15.1948%+999995500+202896101858560+89,947.0260+17.7661%+90,895.3519+18.2175%+3.0227%

Known prime factors (1 factor, 126.5 bits, 0.05021960% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
25197112359067450321537353149104877679370267139126.539245247815231148373287979665867885
32 × 5 × 83939 × 471187 × 56142319 × 2454399168359
2022-02-285614231924543991683596.179e+111,088.42,032.0

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2000-11-25T00:00:00ANONYMOUSv4_computers950003800000---0.002--1.509%
2001-06-17T00:00:00ANONYMOUSv4_computers10000010000000---0.005--1.890%
2002-06-02T00:00:00ANONYMOUSv4_computers327683276800---0.002--1.017%
2002-08-10T00:00:00ANONYMOUSv4_computers655366553600---0.003--1.522%
2003-03-07T00:00:00ANONYMOUSv4_computers13107213107200---0.007--2.148%
2003-11-08T00:00:00ANONYMOUSv4_computers26214426214400---0.014--2.887%
2011-02-07T22:22:00Jocelyn LaroucheManual testing20000002000000---0.016--1.894%
2012-02-26T15:17:00Jocelyn LaroucheManual testing24805552480555---0.020--2.059%
2013-10-13T20:18:00David Campeaui5-2500k259500072660000---0.052--4.898%
2015-01-16T09:21:00thelegendarymudkipi5-4670k10000000250000000---0.188--6.774%
2016-05-13T23:04:30mognutsManual testing281770425---5.28885e-5--0.072%
2020-01-06T20:48:59nordinordiputer120000000250000000012---2.031--10.749%
2022-02-28T02:23:47-Anonymous-T5810100000000020289610196856039126.53989,9470.003179,89427.939%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-11-24T00:00:00ANONYMOUSv4_computers252253--0.002--
2000-04-27T00:00:00ANONYMOUSv4_computers21254--0.010--
2022-03-07T05:45:24LordJuliusManual testing254255--0.010--
2001-02-18T00:00:00ANONYMOUSv4_computers21256--0.038--
2002-03-16T00:00:00ANONYMOUSv4_computers21257--0.076--
2004-02-14T00:00:00ANONYMOUSv4_computers21258--0.152--
2009-01-01T01:52:00Sturle Sundegnom.ifi258259--0.152--
2009-01-24T07:07:00Sturle Sundeghini.ifi259260--0.305--
2013-07-16T20:15:00Sid & AndyBuzz260261--0.610--
2015-08-25T13:23:00NRManual testing261262--1.219--
2016-01-28T21:00:45Gordon SpenceManual testing262263--3.896--
2016-01-28T21:00:45Gordon SpenceManual testing263264--7.792--
2018-03-15T10:11:08Gordon SpenceManual testing264265--14.83--
2020-01-01T19:12:56Gordon SpenceManual testing265266--29.66--
2021-05-26T10:22:38Anton RepkoManual testing266269--415.2--
2021-05-26T10:22:39Anton RepkoManual testing269270--474.5--


ECM factoring results:
Total ECM effort:188.985 GHz-days
Estimated T-Level:34.955
DigitsB1CompleteFacMiss
2011000301.0480.000%
255000056.5810.000%
302500008.2900.025%
3510000000.99137.120%
4030000000.09890.637%
45110000000.00899.181%


ECM Summary

B1B2factorcurvesGHz-days
5000050000003031.812
2500002500000058017.34
10000001000000001,420169.8


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2016-06-01T06:38:57MadPooManual testing1D71AE7FD82446220.001


PRP results:
dateuseridcompidcofactorsres64PRP
2022-02-28T05:05:07Anton Repkotethys
123590674503215373531491048776793702671
7D9755082454AB6Cno
2022-02-28T06:15:19LordJuliusWhiteBox
123590674503215373531491048776793702671
7D9755082454AB6Cno


P-1 factor-bounds graph:
B1 = 1000000000, B2 = 202896101968560 (P-1 stage 2)
B1 = 1000000000 (P-1 stage 1)
B1 = 120000000, B2 = 2500000000 (P-1 stage 2)
B1 = 120000000 (P-1 stage 1)
B1 = 10000000, B2 = 250000000 (P-1 stage 2)
B1 = 10000000 (P-1 stage 1)
B1 = 2595000, B2 = 72660000 (P-1 stage 2)
B1 = 2595000 (P-1 stage 1)
B1 = 2480555 (P-1 stage 1)
B1 = 2000000 (P-1 stage 1)
B1 = 262144, B2 = 26214400 (P-1 stage 2)
B1 = 131072, B2 = 13107200 (P-1 stage 2)
B1 = 100000, B2 = 10000000 (P-1 stage 2)
B1 = 65536, B2 = 6553600 (P-1 stage 2)
B1 = 95000, B2 = 3800000 (P-1 stage 2)
B1 = 262144 (P-1 stage 1)
B1 = 32768, B2 = 3276800 (P-1 stage 2)
B1 = 131072 (P-1 stage 1)
B1 = 100000 (P-1 stage 1)
B1 = 95000 (P-1 stage 1)
B1 = 65536 (P-1 stage 1)
B1 = 32768 (P-1 stage 1)
B1 = 2817, B2 = 70425 (P-1 stage 2)
B1 = 2817 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2022-03-07T05:45:24+00:00