is 2 121787 - 1
has 36662 decimal digits
takes 0.000 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-L545F2A5A05C22505double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual268489.419075.0000%10000000000756670016752650156,120.007933.2749%156,609.426983.3187%
Target2440.000061.3636%20001700000.00005.8892%0.000163.6390%
Difference+24+489.4190+13.6364%+9999998000+756670016582650+156,120.0079+27.3856%+156,609.4269+19.6797%

Known prime factors (1 factor, 135.9 bits, 0.11155651% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1217877912891486800714817703675648151805671439341135.861324866015535349208770380896489436708
22 × 32 × 11 × 443 × 5581 × 43246751 × 673851427 × 11386118753
2023-07-29673851427113861187531.416e+124.76105.1923

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-04-29ANONYMOUSv4_computers10000010000000---0.002--2.153%
2002-06-02ANONYMOUSv4_computers327683276800---0.001--1.182%
2002-07-20ANONYMOUSv4_computers655366553600---0.002--1.747%
2003-02-09ANONYMOUSv4_computers13107213107200---0.003--2.437%
2003-09-29ANONYMOUSv4_computers26214426214400---0.006--3.242%
2008-12-29axnManual testing17600000528000000---0.172--8.589%
2013-02-15alpertronManual testing1000000002000000000---0.771--11.163%
2023-01-13Jocelyn LaroucheManual testing1000000173706132600---35.84--11.854%
2023-02-16Jocelyn LaroucheManual testing1000000522803591310---107.8--12.926%
2023-07-29Oliver Kruse5950X1000000000075667001675265041135.861156,1200.001312,24033.275%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-04-24Oliver KruseOllaptop40000000400000000027--1.031


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-09-22ANONYMOUSv4_computers252253--0.005--
2000-04-19ANONYMOUSv4_computers21254--0.020--
2022-03-07LordJuliusManual testing254255--0.020--
2000-12-21ANONYMOUSv4_computers21256--0.079--
2002-05-25ANONYMOUSv4_computers21257--0.158--
2016-02-23Mark RoseManual testing257258--0.158--
2008-12-31Sturle Sundegiacco.ifi258259--0.315--
2009-01-11Sturle Sundeaalto.ifi259260--0.631--
2013-09-13Sid & AndyBuzz260261--1.261--
2015-08-13NRManual testing261262--2.522--
2016-02-21Gordon SpenceManual testing262263--8.060--
2016-02-21Gordon SpenceManual testing263264--16.12--
2018-05-10chuenkitManual testing264265--30.68--
2019-07-04YxinityManual testing265266--61.36--
2020-02-08Gordon SpenceManual testing266267--122.7--
2022-04-26404_factor_not_foundManual testing267268--245.4--


ECM factoring results:
Total ECM effort:138.607 GHz-days
Estimated T-Level:35.834
DigitsB1CompleteFacMiss
2011000380.4940.000%
255000075.7430.000%
3025000011.8840.001%
3510000001.53621.517%
4030000000.16784.636%
45110000000.01698.444%
50440000000.00199.870%


ECM Summary

B1B2factorcurvesGHz-days
5000050000003310.905
250000250000005767.878
10000001000000001,57286.00
300000030000000026743.82


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1997-01-01Jay R. Hill545F2A5A05C225050.000
2016-06-01MadPooManual testing545F2A5A05C225050.000


PRP results:
dateuseridcompidcofactorsres64PRP
2023-07-29Oliver Kruse5950X
79128914868007148177036756481518056714393
841CC47756E7CA97no


P-1 factor-bounds graph:
B1 = 10000000000, B2 = 756670016752650 (P-1 stage 2)
B1 = 1000000, B2 = 522803591310 (P-1 stage 2)
B1 = 10000000000 (P-1 stage 1)
B1 = 1000000, B2 = 173706132600 (P-1 stage 2)
B1 = 100000000, B2 = 2000000000 (P-1 stage 2)
B1 = 100000000 (P-1 stage 1)
B1 = 17600000, B2 = 528000000 (P-1 stage 2)
B1 = 17600000 (P-1 stage 1)
B1 = 262144, B2 = 26214400 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
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 = 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 = 65536 (P-1 stage 1)
B1 = 32768 (P-1 stage 1)
103
104
105
106
107
108
109
1010
103
104
105
106
107
108
109
1010
1011
1012
1013
1014
1015
TF factor-bounds graph:
268
267
266
265
264
263
262
261
260
259
258
257
256
255
254
253
this exponent TF target: 44
TF double-checked to: 67.9
ECM T-Level=35.83 ~= 102-bit
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Last modified: 2023-09-25T11:53:03+00:00