is 2 21839 - 1
has 6575 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
Actual2671,360.589777.6119 %12000000000360287009607525091,085.820734.6952 %92,446.410385.3795 %
Target2440.000165.9091 %500500000.00001.6009 %0.000166.4548 %
Difference+23+1,360.5896+11.7028 %+11999999500+3602870096025250+91,085.8207+33.0943%+92,446.4102+18.9247 %

Known prime factors (2 factors, 141.6 bits, 0.64854216% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2183981765217826.2851872
24 × 32 × 13
-16165.752e-107.424e-91.511e-8
218395294823466947557486502138226533975135115.3501212240365160391383877956460125
3 × 53 × 11 × 41 × 113 × 15692280841 × 4042187139169
2017-10-281569228084140421871391696.823e+12109.07190.86

1 Composite Factors:
P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2016-11-18kkmrkkblmbrbkManual testing5000000001000000000012
skipped known factor: 81765217
---42.369%
2023-05-08nordisweet16_30.9b31200000000012000000000
skipped known factor: 81765217
--5.56839.286%
2023-09-29nordisweet16_30.8b14120000000003602870096075250
skipped known factor: 81765217
--156,79173.418%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-06-28ATHec2-P_11000000001000000000027--0.316


Trial Factoring results:
5758596061626364656667
No TF results for M21839


ECM factoring results:
Total ECM effort:17.897 GHz-days
Estimated T-Level:35.903
DigitsB1CompleteFacMiss
2011000357.1690.000%
255000074.1640.000%
3025000012.0700.001%
3510000001.61319.938%
4030000000.18183.469%
45110000000.01898.256%
50440000000.00299.849%


ECM Summary

B1B2factorcurvesGHz-days
500005000000300.009
250000250000004750.788
1000000100000000850.568
10000001000000001,3368.920
30000003000000003807.612


Lucas-Lehmer results:
No L-L results for M21839


PRP results:
dateuseridcompidcofactorsres64
2017-09-21Oliver KrusePRP
81765217
8B4D9A71B9618F10
2017-09-21Oliver KruseManual testing
81765217
8B4D9A71B9618F10
2017-10-12kkmrkkblmbrbkManual testing
81765217
8B4D9A71B9618F10
2017-10-28Oliver KruseGTX-0
81765217
52948234669475574865021382265339751
A6A5C9608249851C
2017-10-29kkmrkkblmbrbkold
81765217
52948234669475574865021382265339751
A6A5C9608249851C


CERT results:
No CERT results for M21839


P-1 factor-bounds graph:
B1 = 12000000000, B2 = 3602870096075250 (P-1 stage 2)
B1 = 12000000000 (P-1 stage 1)
B1 = 500000000, B2 = 10000000000 (P-1 stage 2)
B1 = 500000000 (P-1 stage 1)
100
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1010
1011
100
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109
1010
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1016
TF factor-bounds graph:
this exponent TF target: 44
TF double-checked to: 67
ECM T-Level=35.9 ~= 103-bit
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2120
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Last modified: 2024-03-13T02:15:48+00:00