is 2 28807 - 1
has 8672 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-LDBBE6240726A93B4double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual2671,031.482577.6119%8000000000225317262487317098,054.726034.0376%99,086.208585.2323%
Target2440.000165.9091%500500000.00001.7377%0.000166.5015%
Difference+23+1,031.4825+11.7028%+7999999500+2253172624823170+98,054.7260+32.2998%+99,086.2084+18.7308%

Known prime factors (1 factor, 142.3 bits, 0.49397253% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
28807685751894552340687313356666815875081832483943142.299119025218619144771637684706289421856117
7 × 211 × 227 × 619 × 43579469 × 1438212757 × 9150333341249
2023-07-27143821275791503333412496.519e+12399.27743.70

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-04-29ANONYMOUSv4_computers10000010000000---0.001--1.938%
2001-08-18Alex Kruppav4_computers1000000100000000---0.005--4.731%
2002-04-28ANONYMOUSv4_computers163841638400---8.36694e-5--0.646%
2002-06-09ANONYMOUSv4_computers327683276800---0.000--1.041%
2002-07-20ANONYMOUSv4_computers655366553600---0.000--1.560%
2003-02-02ANONYMOUSv4_computers13107213107200---0.001--2.204%
2003-03-27ANONYMOUSv4_computers26214426214400---0.001--2.965%
2003-04-03ANONYMOUSv4_computers52428852428800---0.003--3.833%
2003-04-27ANONYMOUSv4_computers1048576104857600---0.005--4.801%
2003-05-19ANONYMOUSv4_computers2097152209715200---0.011--5.860%
2003-07-13ANONYMOUSv4_computers4194304419430400---0.021--7.004%
2003-09-29ANONYMOUSv4_computers8388608838860800---0.043--8.227%
2003-10-08ANONYMOUSv4_computers167772161677721600---0.086--9.512%
2013-11-07David Campeaui5-2500k20454500010636340000---0.617--13.438%
2017-05-30mikrS0581200000000096000000000012---50.84--22.228%
2023-07-27masserManual testing8000000000225317262487317043142.29998,0553.17357e-5196,10934.038%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-05-07ATH5960X50000000010150000000027--4.914
2023-07-07masserManual testing250000000100000000009137--0.719


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-10-21ANONYMOUSv4_computers252253--0.021--
2000-03-15ANONYMOUSv4_computers253254--0.042--
2000-10-15ANONYMOUSv4_computers21256--0.333--
2002-12-02ANONYMOUSv4_computers21257--0.666--
2016-02-23LaurVManual testing257258--0.666--
2009-01-14Sturle Sundehoffman.ifi258259--1.333--
2009-02-07Sturle Sundezumthor.ifi259260--2.666--
2012-04-02bcp19Manual testing260261--5.332--
2012-04-02bcp19Manual testing261262--10.66--
2016-09-20Sid & AndyMrs_Potato_Head262263--34.08--
2018-04-09YxinityElena263264--68.15--
2018-04-10YxinityManual testing263264--68.15--
2019-07-20YxinityYGSMainFrame264265--129.7--
2019-07-21YxinityManual testing264265--129.7--
2020-05-24YxinityManual testing265266--259.4--
2020-05-24YxinityManual testing265266--259.4--


ECM factoring results:
Total ECM effort:3,118.785 GHz-days
Estimated T-Level:42.292
DigitsB1CompleteFacMiss
20110001,542.5670.000%
2550000434.3390.000%
3025000099.8600.000%
35100000018.9920.000%
4030000003.1074.473%
45110000000.45863.232%
50440000000.06293.991%
551100000000.00899.222%


ECM Summary

B1B2factorcurvesGHz-days
10000001000000002262.597
30000003000000003,057105.4
30000004000000002,00076.44
11000000110000000011013.91
11000000351333910307281,018
430000002404906604262041,902


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1997-01-01George WoltmanDBBE6240726A93B41.58679e-5
2015-04-11MadPooManual testingDBBE6240726A93B41.58679e-5


PRP results:
dateuseridcompidcofactorsres64PRP
2023-07-27masserManual testing
6857518945523406873133566668158750818324839
39ECD250F4AFCB__no
2023-07-30Naegi Makoto5950X
6857518945523406873133566668158750818324839
39ECD250F4AFCB7Cno


P-1 factor-bounds graph:
B1 = 8000000000, B2 = 2253172624873170 (P-1 stage 2)
B1 = 12000000000, B2 = 960000000000 (P-1 stage 2)
B1 = 12000000000 (P-1 stage 1)
B1 = 8000000000 (P-1 stage 1)
B1 = 204545000, B2 = 10636340000 (P-1 stage 2)
B1 = 204545000 (P-1 stage 1)
B1 = 16777216, B2 = 1677721600 (P-1 stage 2)
B1 = 8388608, B2 = 838860800 (P-1 stage 2)
B1 = 4194304, B2 = 419430400 (P-1 stage 2)
B1 = 16777216 (P-1 stage 1)
B1 = 2097152, B2 = 209715200 (P-1 stage 2)
B1 = 8388608 (P-1 stage 1)
B1 = 1048576, B2 = 104857600 (P-1 stage 2)
B1 = 1000000, B2 = 100000000 (P-1 stage 2)
B1 = 4194304 (P-1 stage 1)
B1 = 524288, B2 = 52428800 (P-1 stage 2)
B1 = 2097152 (P-1 stage 1)
B1 = 262144, B2 = 26214400 (P-1 stage 2)
B1 = 1048576 (P-1 stage 1)
B1 = 1000000 (P-1 stage 1)
B1 = 131072, B2 = 13107200 (P-1 stage 2)
B1 = 100000, B2 = 10000000 (P-1 stage 2)
B1 = 524288 (P-1 stage 1)
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 = 16384, B2 = 1638400 (P-1 stage 2)
B1 = 100000 (P-1 stage 1)
B1 = 65536 (P-1 stage 1)
B1 = 32768 (P-1 stage 1)
B1 = 16384 (P-1 stage 1)
103
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109
1010
1011
103
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1016
TF factor-bounds graph:
266
265
264
263
262
261
260
259
258
257
256
254
253
this exponent TF target: 44
TF double-checked to: 67.9
ECM T-Level=42.29 ~= 124-bit
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Last modified: 2023-09-25T11:53:03+00:00