is 2 515861 - 1
has 155290 decimal digits
takes 0.008 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
Actualunknown200000067331464207.797146.1347%7.797146.1347%
Target2440.000056.8182%90003000000.000514.5763%0.000563.1125%
Difference-440.0000-56.8182%+1991000+6732846420+7.7966+31.5585%+7.7966-16.9778%

Known prime factors (3 factors, 205.3 bits, 0.03979373% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
515861514829279928.940499
499
-14997.681e-115.949e-71.075e-6
51586166801845716521413151532272.5006474791243815816
23 × 37 × 1231 × 17769532691
2015-06-121231177695326913,521.820.47238.236
5158611815849319502875744727429347896732103.84017600180276303846818497903
3 × 37 × 83 × 4339 × 20693 × 367771 × 57852943
2022-12-18367771578529433.588e+110.07400.1245

4 Composite Factors:
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2016-03-16alpertronManual testing15000005000000012-
skipped known factor: 514829279
--0.088--32.820%
2022-12-18USAFSSUSAFSACS2000000673314642032103.8407.7970.01515.5946.135%


Trial Factoring results:
No TF results for M515861


ECM factoring results:
Total ECM effort:16.101 GHz-days
Estimated T-Level:26.435
DigitsB1CompleteFacMiss
201100023.8990.000%
25500003.0284.840%
302500000.28775.049%
3510000000.02297.832%
4030000000.00199.860%


ECM Summary

B1B2factorcurvesGHz-days
5000050000001953.137
500005000000861.383
2500002500000014411.58


Lucas-Lehmer results:
No L-L results for M515861


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-27Oliver KruseGTX-1
514829279
6680184571652141315153
85E0AC36931BC5__no
2017-09-28Oliver KruseManual testing
514829279
6680184571652141315153
85E0AC36931BC5__no
2017-11-07kkmrkkblmbrbkc4.xlarge
514829279
6680184571652141315153
85E0AC36931BC5__no
2020-04-19Oliver KruseAddPrpType5
514829279
6680184571652141315153
93727494886514__no
2022-12-18Kevin_9611PRP-CF
514829279
6680184571652141315153
18158493195028757447274293478967
9372749488651463no


P-1 factor-bounds graph:
B1 = 2000000, B2 = 6733146420 (P-1 stage 2)
B1 = 1500000, B2 = 50000000 (P-1 stage 2)
B1 = 2000000 (P-1 stage 1)
B1 = 1500000 (P-1 stage 1)
100
101
102
103
104
105
106
107
100
101
102
103
104
105
106
107
108
109
1010
1011
TF factor-bounds graph:
this exponent TF target: 44
TF double-checked to: 67.7
ECM T-Level=26.44 ~= 71-bit
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2100
2110
Last modified: 2023-03-25T13:08:14+00:00