is 2 1853387 - 1
has 557926 decimal digits
takes 0.101 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-LA89B51A95AA077D1double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26716.032268.6567 %500000150000000.10155.0763 %16.133770.2478 %
Target2610.165765.5738 %90007500000.00391.6316 %0.169666.1355 %
Difference+6+15.8665+3.0829 %+491000+14250000+0.0976+3.4448%+15.9641+4.1124 %

Known prime factors (2 factors, 124.7 bits, 0.00673028% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
185338716464976186507424631960.514444186135613
11 × 29 × 3851 × 361577
2008-10-2238513615770.08290.00180.0029
1853387215461848685005255912064.2245812651342785
3 × 5 × 7 × 53 × 1044501589
2017-08-165310445015891.92044.47658.3608

1 Composite Factors:
P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2016-03-16alpertronManual testing5000001500000012
skipped known factor: 1646497618650742463
---8.877%


Trial Factoring results:
5758596061626364656667
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2003-01-09ANONYMOUSv4_computers212580.021
2022-03-08LordJuliusManual testing261262
2022-03-08LordJuliusManual testing262263
2022-03-08LordJuliusManual testing263264
2017-08-16TJAOIManual testing264265*
64.224
20
0.452


ECM factoring results:
Total ECM effort:39.156 GHz-days
Estimated T-Level:25.707
DigitsB1CompleteFacMiss
201100014.8570.000%
25500001.67018.833%
302500000.14186.819%
3510000000.01099.034%


ECM Summary

B1B2factorcurvesGHz-days
10.155
500005000000553.804
50000660000019315.05
250000400000004720.14


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-03-26ANONYMOUSv4_computersA89B51A95AA077D10.101


PRP results:
dateuseridcompidcofactorsres64
2017-09-28alpertronManual testing
1646497618650742463
21546184868500525591
C8189608D02EE386
2017-10-19Oliver KruseThreadripper-PC
1646497618650742463
21546184868500525591
C8189608D02EE386


CERT results:
No CERT results for M1853387


P-1 factor-bounds graph:
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
100
101
102
103
104
105
106
100
101
102
103
104
105
106
107
108
109
1010
TF factor-bounds graph:
264
263
262
258
this exponent TF target: 61
TF double-checked to: 67
ECM T-Level=25.71 ~= 69-bit
250
260
270
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Last modified: 2024-03-03T02:29:32+00:00