is 2 254281 - 1
has 76547 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-L8D42A89CD7E78B0Bdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual267116.854773.1343%30000000101706782076904,508.666423.4451%4,625.521179.4330%6.2987%
PrimeNet2400.000055.0000%2600700000.000114.2400%0.000161.4080%6.4080%
GPU722440.000059.0909%45001100000.000110.1869%0.000163.2583%4.1673%
Difference+23+116.8546+14.0434%+29995500+10170678097690+4,508.6663+13.2583%+4,625.5210+16.1748%+16.1748%

Known prime factors (1 factor, 95.8 bits, 0.03768473% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
254281701824278266954309328698231772995.825138001714297756086638148
22 × 3 × 19 × 409 × 13567 × 109079339960447
2020-01-13135671090793399604473.352e+1048,35290,309

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2000-12-07T00:00:00ANONYMOUSv4_computers950003800000---0.002--2.198%
2001-06-17T00:00:00ANONYMOUSv4_computers10000010000000---0.005--2.719%
2002-06-02T00:00:00ANONYMOUSv4_computers327683276800---0.002--1.557%
2002-08-10T00:00:00ANONYMOUSv4_computers655366553600---0.003--2.239%
2003-03-07T00:00:00ANONYMOUSv4_computers13107213107200---0.007--3.049%
2003-11-08T00:00:00ANONYMOUSv4_computers26214426214400---0.014--3.976%
2011-02-07T22:22:00Jocelyn LaroucheManual testing20000002000000---0.016--2.607%
2012-02-26T15:17:00Jocelyn LaroucheManual testing24513762451376---0.020--2.803%
2013-10-13T23:21:00David Campeaui5-2500k257000071960000---0.052--6.345%
2015-01-16T14:34:00thelegendarymudkipi5-4670k10000000250000000---0.188--8.557%
2016-05-13T23:04:30mognutsManual testing284371075---5.33767e-5--0.141%
2021-08-30T19:32:37Oliver KruseOllaptop30000000363000000024---1.840--12.855%
2022-04-24T15:52:55Oliver KruseThreadripper-PC3000000010170678207690---4,509--23.445%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-11-24T00:00:00ANONYMOUSv4_computers252253--0.002--
2000-04-27T00:00:00ANONYMOUSv4_computers21254--0.009--
2000-12-07T00:00:00ANONYMOUSv4_computers21255--0.019--
2001-02-18T00:00:00ANONYMOUSv4_computers21256--0.038--
2002-03-16T00:00:00ANONYMOUSv4_computers21257--0.076--
2004-02-14T00:00:00ANONYMOUSv4_computers21258--0.151--
2008-12-31T22:28:00Sturle Sundegobi.ifi258259--0.151--
2009-01-24T08:50:00Sturle Sundeginjtje.ifi259260--0.302--
2013-07-21T12:55:00Sid & AndyBuzz260261--0.604--
2015-08-25T13:23:00NRManual testing261262--1.208--
2016-01-30T13:38:40Gordon SpenceManual testing262263--3.861--
2016-01-30T13:38:40Gordon SpenceManual testing263264--7.721--
2018-03-15T10:11:08Gordon SpenceManual testing264265--14.69--
2020-01-01T19:12:56Gordon SpenceManual testing265266--29.39--


ECM factoring results:

Old Calculation Method

Total ECM effort:23.586 GHz-days
Estimated T-Level:29.859
DigitsB1CurvesCompleteFacMiss
2011000900 / 1009.0000.012%
2550000900 / 2803.2143.995%
30250000622 / 6400.97237.809%
35100000037 / 15800.02397.685%

New Calculation Method

Total ECM effort:23.586 GHz-days
Estimated T-Level:29.859
DigitsB1CompleteFacMiss
201100063.0030.000%
25500008.9160.013%
302500000.97537.716%
3510000000.08691.785%
4030000000.00699.369%


ECM Summary

B1B2factorcurvesGHz-days
5000050000002781.663
2500002500000058517.50
1000000100000000374.427


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2001-10-13T00:00:00ANONYMOUSv4_computers8D42A89CD7E78B0B0.001


PRP results:
dateuseridcompidcofactorsres64PRP
2020-01-13T21:12:27nordinordiputer
70182427826695430932869823177
D692115510C0E325no
2020-01-13T21:38:50harleei5-5250U_1600
70182427826695430932869823177
D692115510C0E325no


P-1 factor-bounds graph:
B1 = 30000000, B2 = 10170678207690 (P-1 stage 2)
B1 = 30000000, B2 = 3630000000 (P-1 stage 2)
B1 = 30000000 (P-1 stage 1)
B1 = 10000000, B2 = 250000000 (P-1 stage 2)
B1 = 10000000 (P-1 stage 1)
B1 = 2570000, B2 = 71960000 (P-1 stage 2)
B1 = 2570000 (P-1 stage 1)
B1 = 2451376 (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 = 2843, B2 = 71075 (P-1 stage 2)
B1 = 2843 (P-1 stage 1)
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TF factor-bounds graph:
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Last modified: 2022-04-24T15:52:55+00:00