is 2 8761 - 1
has 2638 decimal digits
takes 0.000 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual2673,391.612579.1045%4000000004000000000.07077.5384%3,391.683380.6797%
Target2440.000368.1818%500100000.00001.2134%0.000368.5679%
Difference+23+3,391.6123+10.9227%+399999500+399990000+0.0707+6.3250%+3,391.6830+12.1118%

Known prime factors (6 factors, 373.1 bits, 4.25856055% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
8761192743617.55611
11
-1111.998e-122.732e-103.599e-10
8761210860647754711444.2611203405135
3 × 5 × 103 × 778903
-1037789030.00037.521e-61.401e-5
8761275216539464728391754.6111570691356379
31 × 50667463109
-31506674631090.29170.48810.9117
87612527383755331979271857.81014424059783883
3 × 19 × 31 × 311 × 3307 × 7937
-330779372.87586.293e-71.190e-6
87619787709430642932411859.76455859544747420
22 × 3 × 5 × 337 × 5857 × 471673
-585747167312.1815.523e-68.487e-6
876174136081320741938814571703771003912252907342139.08942310284967892899677303791673897906776
23 × 7 × 137849 × 633151 × 8656593143205309812301179
2018-06-0563315186565931432053098123011791.940e+138.339e+131.558e+14

57 Composite Factors:
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2021-08-27Seth_TrManual testing100000000100000000-
skipped known factor: 192743
skipped known factor: 21086064775471
skipped known factor: 252738375533197927
skipped known factor: 978770943064293241
--0.018--5.594%
2021-08-27Seth_TrManual testing400000000400000000-
skipped known factor: 192743
skipped known factor: 21086064775471
skipped known factor: 252738375533197927
skipped known factor: 978770943064293241
--0.071--7.538%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2005-03-20ANONYMOUSv4_computers??72.168226,8062.31664e-614,758


ECM factoring results:
Total ECM effort:3,117.511 GHz-days
Estimated T-Level:46.509
DigitsB1CompleteFacMiss
20110005,583.8000.000%
25500001,577.6920.000%
30250000425.2530.000%
35100000087.9310.000%
40300000015.2530.000%
45110000002.29010.122%
50440000000.30273.942%
551100000000.03696.490%
602600000000.00499.627%


ECM Summary

B1B2factorcurvesGHz-days
30000003000000003,21724.56
30000003000000007025.358
11000000365788846629,6003,088


Lucas-Lehmer results:
No L-L results for M8761


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-21Oliver KruseOliver-PC75966DB2719532__?
2017-09-21Oliver KruseManual testing75966DB2719532__?
2017-10-02kkmrkkblmbrbkManual testing
192743
21086064775471
27521653946472839
252738375533197927
978770943064293241
75966DB2719532__no
2017-12-07ATHManual testing
192743
21086064775471
27521653946472839
252738375533197927
978770943064293241
75966DB2719532__no
2018-06-05ATHec2-PRPCF
192743
21086064775471
27521653946472839
252738375533197927
978770943064293241
741360813207419388145717037710039122529073
0AF394F4D3633C__no
2018-06-05kkmrkkblmbrbkc5.large
192743
21086064775471
27521653946472839
252738375533197927
978770943064293241
741360813207419388145717037710039122529073
0AF394F4D3633C__no


P-1 factor-bounds graph:
B1 = 400000000 (P-1 stage 1)
B1 = 100000000 (P-1 stage 1)
100
101
102
103
104
105
106
107
108
109
100
101
102
103
104
105
106
107
108
109
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
TF factor-bounds graph:
2
this exponent TF target: 44
TF double-checked to: 67.7
ECM T-Level=46.51 ~= 138-bit
250
260
270
280
290
2100
2110
2120
2130
2140
Last modified: 2023-03-23T17:39:31+00:00