is 2 1920203 - 1
has 578039 decimal digits
takes 0.104 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L4491BC838ED677CDdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26831.040969.1176 %1820000053960339160232.614217.4083 %263.655174.4937 %
Target2610.160065.5738 %100008500000.00441.7616 %0.164466.1802 %
Difference+7+30.8810+3.5439 %+18190000+53959489160+232.6098+15.6467%+263.4907+8.3135 %

Known prime factors:
No known factors for M1920203

P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2011-08-31kurlyhex10000003000000012--0.20310.445%
2018-01-07mikrS063800000032000000012--1.96615.747%
2023-01-11JossManual testing19202031890473970--9.9917.582%
2023-06-21JossJoss19202035395249860--28.2019.204%
2023-10-09Sid & AndyPterodactyl1820000053960339160--281.925.410%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2022-08-13masserManual testing15000005400000027--0.400


Trial Factoring results:
575859606162636465666768
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2009-06-02Architects Cubedi4l_12602610.080
2011-08-27GrunwalderGIMPManual testing212630.831
2016-02-23Mark RoseManual testing212630.751
2015-05-17snme2pm1Manual testing2632652.968
2015-09-02ramgeisManual testing2652663.892
2018-06-04TJAOIManual testing2662677.783
2019-04-28chuenkitManual testing26726815.57


ECM factoring results:
Total ECM effort:37.767 GHz-days
Estimated T-Level:25.674
DigitsB1CompleteFacMiss
201100014.2390.000%
25500001.60020.198%
302500000.13587.395%
3510000000.00999.081%


ECM Summary

B1B2factorcurvesGHz-days
50000500000020113.85
500006600000503.918
250000400000004318.53
25000018016845011.469


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-01-17ANONYMOUSv4_computers4491BC838ED677CD0.104
2015-06-27MadPooManual testing4491BC838ED677CD0.104


PRP results:
No PRP results for M1920203


CERT results:
No CERT results for M1920203


P-1 factor-bounds graph:
B1 = 18200000, B2 = 53960339160 (P-1 stage 2)
B1 = 1920203, B2 = 5395249860 (P-1 stage 2)
B1 = 1920203, B2 = 1890473970 (P-1 stage 2)
B1 = 8000000, B2 = 320000000 (P-1 stage 2)
B1 = 18200000 (P-1 stage 1)
B1 = 8000000 (P-1 stage 1)
B1 = 1000000, B2 = 30000000 (P-1 stage 2)
B1 = 1920203 (P-1 stage 1)
B1 = 1000000 (P-1 stage 1)
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108
105
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107
108
109
1010
1011
TF factor-bounds graph:
268
267
266
265
263
261
this exponent TF target: 61
TF double-checked to: 67
ECM T-Level=25.67 ~= 69-bit
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Last modified: 2024-03-13T02:15:48+00:00