is 2 61987 - 1
has 18660 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
Actual267479.357276.1194 %1000000000891895209905708,358.932028.5933 %8,838.289382.9476 %
Target2440.000063.6364 %500500000.00002.1691 %0.000064.4251 %
Difference+23+479.3572+12.4830 %+999999500+89189520940570+8,358.9320+26.4242%+8,838.2892+18.5225 %

Known prime factors (2 factors, 141.0 bits, 0.22741196% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
619872572443257696091547.8702074986092
22 × 3617 × 143419
1999-08-3136171434190.00041.932e-52.510e-5
61987105828758471312644473260605912993.09685363671795144662972285
5 × 1241704567 × 13749433490671
2017-01-031241704567137494334906715.341e+101,290.42,406.3

1 Composite Factors:
P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2016-10-15kkmrkkblmbrbkManual testing100000000200000000012
skipped known factor: 257244325769609
---39.890%
2022-11-13George WoltmanSkylakeX10000000001000000000
skipped known factor: 257244325769609
--2.69935.259%
2022-11-20George WoltmanSkylakeX100000000089189520990570
skipped known factor: 257244325769609
--13,11667.267%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-04-26ATHcolab-Pp210000000100000000027--0.117


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
1999-08-31ANONYMOUSv4_computers??
47.870
15


ECM factoring results:
Total ECM effort:165.217 GHz-days
Estimated T-Level:32.899
DigitsB1CompleteFacMiss
2011000171.1570.000%
255000032.8980.000%
302500004.8550.779%
3510000000.58056.005%
4030000000.05894.389%
45110000000.00599.513%


ECM Summary

B1B2factorcurvesGHz-days
110001100000300.007
5000050000002740.320
250000250000005303.279
25000025000000550.340
10000001000000003038.766
100000033080597555014.15
160592254146839645023.14
186229556380019805024.25
186229570411383685029.90
2455913146641047195061.07


Lucas-Lehmer results:
No L-L results for M61987


PRP results:
dateuseridcompidcofactorsres64
2017-09-21Oliver KruseOliver-PC
257244325769609
10582875847131264447326060591
5E3C2E01C572E36C
2017-09-21Oliver KruseManual testing
257244325769609
10582875847131264447326060591
5E3C2E01C572E36C
2017-11-06kkmrkkblmbrbkc4.xlarge
257244325769609
10582875847131264447326060591
5E3C2E01C572E36C
2020-04-17Oliver KruseAddPrpType5
257244325769609
10582875847131264447326060591
14A4E00A59FBC926
2024-02-03Wentao HuangManual testing
257244325769609
10582875847131264447326060591
14A4E00A59FBC926


CERT results:
No CERT results for M61987


P-1 factor-bounds graph:
B1 = 1000000000, B2 = 89189520990570 (P-1 stage 2)
B1 = 1000000000 (P-1 stage 1)
B1 = 100000000, B2 = 2000000000 (P-1 stage 2)
B1 = 100000000 (P-1 stage 1)
102
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105
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109
1010
102
103
104
105
106
107
108
109
1010
1011
1012
1013
1014
TF factor-bounds graph:
this exponent TF target: 44
TF double-checked to: 67
ECM T-Level=32.9 ~= 93-bit
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Last modified: 2024-03-15T04:28:18+00:00