is 2 51481 - 1
has 15498 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
Actual267577.182276.1194%68000000084490380635661065,821.272830.9249%66,398.455083.5045%
Target2440.000063.6364%500500000.00002.0571%0.000164.3844%
Difference+23+577.1822+12.4830%+679999500+844903806306610+65,821.2728+28.8678%+66,398.4550+19.1201%

Known prime factors (3 factors, 221.3 bits, 0.42990754% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
5148149980843671032.21948543
3 × 11 × 1471
-1114711.675e-81.295e-72.146e-7
51481821868584091111446.224798225155
5 × 7 × 13 × 223 × 7867
2008-08-2622378670.00029.143e-71.144e-6
514811024623336728769196260374317228623667759076944142.87899514708021286415984574339778619652664
23 × 1597 × 60029 × 17846471 × 43318789 × 167842756556389
2023-04-11433187891678427565563893.672e+1213,07524,421

4 Composite Factors:
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2016-09-19kkmrkkblmbrbkManual testing100000000200000000012-
skipped known factor: 4998084367
skipped known factor: 82186858409111
--0.291--11.159%
2023-04-11JacobZGreatLakes68000000084490380635661044142.87865,8210.000131,64330.925%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-04-26ATHcolab-Pp110000000100000000027--0.097


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2008-08-26ANONYMOUSManual testing??46.224141.37950e-60.0002.79854e-6


ECM factoring results:
Total ECM effort:18.454 GHz-days
Estimated T-Level:32.761
DigitsB1CompleteFacMiss
2011000187.7030.000%
255000033.9000.000%
302500004.7750.844%
3510000000.55257.566%
4030000000.05394.795%
45110000000.00499.562%


ECM Summary

B1B2factorcurvesGHz-days
5000050000002830.291
250000250000006033.102
100000010000000073215.06


Lucas-Lehmer results:
No L-L results for M51481


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-21Oliver KruseOllaptop
4998084367
82186858409111
04AB47F50FB00F__no
2017-09-21Oliver KruseManual testing
4998084367
82186858409111
04AB47F50FB00F__no
2017-10-13kkmrkkblmbrbkManual testing
4998084367
82186858409111
04AB47F50FB00F__no
2020-04-17Oliver KruseManual testing
4998084367
82186858409111
E2446BBC6F3EA2__no
2023-04-11JacobZGreatLakes
4998084367
82186858409111
10246233367287691962603743172286236677590769
E2446BBC6F3EA225no


P-1 factor-bounds graph:
B1 = 680000000, B2 = 844903806356610 (P-1 stage 2)
B1 = 680000000 (P-1 stage 1)
B1 = 100000000, B2 = 2000000000 (P-1 stage 2)
B1 = 100000000 (P-1 stage 1)
100
101
102
103
104
105
106
107
108
109
100
101
102
103
104
105
106
107
108
109
1010
1011
1012
1013
1014
1015
TF factor-bounds graph:
2
this exponent TF target: 44
TF double-checked to: 67.9
ECM T-Level=32.76 ~= 92-bit
250
260
270
280
290
2100
2110
2120
2130
2140
2150
Last modified: 2023-09-25T11:53:03+00:00