is 2 7428803 - 1
has 2236293 decimal digits
takes 1.620 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-L6657E738373F809Fdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual272128.733268.0556%310000011007976980190.554511.3749%319.287771.6892%
Target2673.999865.6716%5000011000000.03392.4336%4.033766.5071%
Difference+5+124.7334+2.3839%+3050000+11006876980+190.5206+8.9413%+315.2539+5.1822%

Known prime factors (1 factor, 126.8 bits, 0.00170707% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
742880314964775942098207553661921243900469652139126.81510072131366317162774179044217420
22 × 5 × 7 × 41 × 97 × 26861 × 390809 × 1180757 × 1459454273		2023-03-05118075714594542731.859e+1025.49446.957

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2002-01-22ANONYMOUSv4_computers35000271250---0.015--0.750%
2012-09-10NesowaEPC850001423750---0.050--1.559%
2016-08-16Squeeky_SquirrelP4_2600230000580750012---0.169--2.680%
2023-03-05DRobinsonPE5500X31000001100797698039126.815190.63.240381.111.375%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1998-07-21ANONYMOUSv4_computers21261--0.041--
1998-07-29ANONYMOUSv4_computers21262--0.083--
1998-12-27ANONYMOUSv4_computers21263--0.215--
2012-03-17David CampeauManual testing263264--0.264--
2013-11-25David CampeauManual testing264265--0.503--
2015-06-21VictordeHollanderManual testing265266--1.006--
2016-05-20america64Manual testing266267--2.012--
2016-05-28america64Manual testing267268--4.024--
2016-06-04ramgeisManual testing268269--8.047--
2016-06-04ramgeisManual testing269270--16.09--
2016-06-04ramgeisManual testing270271--32.19--
2021-09-28SRBaseManual testing271272--64.38--


ECM factoring results:
Total ECM effort:1.989 GHz-days
Estimated T-Level:1.154
DigitsB1CompleteFacMiss
20110000.23179.392%
25500000.02197.887%
302500000.00199.865%


ECM Summary

B1B2factorcurvesGHz-days
50000500000061.989


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-07-12ANONYMOUSv4_computers6657E738373F809F1.620
2002-02-24ANONYMOUSv4_computers6657E738373F809F1.620


PRP results:
dateuseridcompidcofactorsres64PRP
2023-03-12TravisJankKRMPNCDT2
149647759420982075536619212439004696521
DA1535DC1298F5D5no


P-1 factor-bounds graph:
B1 = 3100000, B2 = 11007976980 (P-1 stage 2)
B1 = 3100000 (P-1 stage 1)
B1 = 230000, B2 = 5807500 (P-1 stage 2)
B1 = 230000 (P-1 stage 1)
B1 = 85000, B2 = 1423750 (P-1 stage 2)
B1 = 85000 (P-1 stage 1)
B1 = 35000, B2 = 271250 (P-1 stage 2)
B1 = 35000 (P-1 stage 1)
103
104
105
106
107
103
104
105
106
107
108
109
1010
1011
TF factor-bounds graph:
272
271
270
269
268
267
266
265
264
263
262
261
this exponent TF target: 67
TF double-checked to: 67.7
ECM T-Level=1.15 ~= -13-bit
250
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270
280
290
2100
2110
2120
2130
Last modified: 2023-03-25T13:08:14+00:00