is 2 891557 - 1
has 268386 decimal digits
takes 0.022 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-L32D6205300084D93double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26733.328170.1493 %80000001000038270019.424214.4282 %52.752374.4562 %
Target2440.000054.5455 %1500030000000.006217.9685 %0.006262.7129 %
Difference+23+33.3281+15.6038 %+7985000+9997382700+19.4180-3.5403 %+52.7461+11.7432 %

Known prime factors (1 factor, 83.1 bits, 0.00932423% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
891557105891058157916214912440172683.1315938546731051195544
23 × 742318341381399443
2009-08-3187423183413813994433,540,2591.422e+92.656e+9

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2002-01-08ANONYMOUSv4_computers2000200000--0.00012.125%
2002-02-17ANONYMOUSv4_computers4096409600--0.00115.046%
2002-04-20ANONYMOUSv4_computers8192819200--0.00217.842%
2002-05-25ANONYMOUSv4_computers163841638400--0.00420.602%
2002-07-14ANONYMOUSv4_computers32768327680012--0.00723.317%
2002-12-25ANONYMOUSv4_computers65537655370012--0.01525.981%
2003-08-25ANONYMOUSv4_computers1310721310720012--0.02928.586%
2016-03-17alpertronManual testing3000001000000012---28.456%
2024-03-18Anton TsvetkovManual testing800000010000382700--19.4249.553%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2001-12-08ANONYMOUSv4_computers212570.022
2003-08-31ANONYMOUSv4_computers212580.043
2022-03-07LordJuliusManual testing258259
2004-09-16Sturle Sundev4_computers212600.086


ECM factoring results:
Total ECM effort:13.982 GHz-days
Estimated T-Level:25.655
DigitsB1CompleteFacMiss
201100014.7310.000%
25500001.61319.937%
302500000.13187.717%
3510000000.00999.131%


ECM Summary

B1B2factorcurvesGHz-days
10.046
5000050000002797.763
25000025000000446.173


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2002-01-28ANONYMOUSv4_computers32D6205300084D930.022


PRP results:
dateuseridcompidcofactorsres64
2017-09-28Oliver KruseGTX-1
10589105815791621491244017
2201CA516A3AF11F
2017-10-14Oliver KruseThreadripper-PC
10589105815791621491244017
2201CA516A3AF11F
2017-12-19ATHec2-1xh
10589105815791621491244017
2201CA516A3AF11F
2020-04-22Oliver KruseAddPrpType5
10589105815791621491244017
58B4647AA256027B


CERT results:
No CERT results for M891557


P-1 factor-bounds graph:
B1 = 8000000, B2 = 10000382700 (P-1 stage 2)
B1 = 8000000 (P-1 stage 1)
B1 = 131072, B2 = 13107200 (P-1 stage 2)
B1 = 300000, B2 = 10000000 (P-1 stage 2)
B1 = 65537, B2 = 6553700 (P-1 stage 2)
B1 = 300000 (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 = 65537 (P-1 stage 1)
B1 = 8192, B2 = 819200 (P-1 stage 2)
B1 = 32768 (P-1 stage 1)
B1 = 4096, B2 = 409600 (P-1 stage 2)
B1 = 16384 (P-1 stage 1)
B1 = 2000, B2 = 200000 (P-1 stage 2)
B1 = 8192 (P-1 stage 1)
B1 = 4096 (P-1 stage 1)
B1 = 2000 (P-1 stage 1)
100
101
102
103
104
105
106
107
100
101
102
103
104
105
106
107
108
109
1010
1011
1012
1013
1014
1015
1016
1017
1018
TF factor-bounds graph:
260
259
258
257
this exponent TF target: 44
TF double-checked to: 67
ECM T-Level=25.66 ~= 69-bit
250
260
270
280
290
JSON version of this page
Last modified: 2024-03-18T18:53:09+00:00