is 2 21055579 - 1
has 6338361 decimal digits
takes 14.922 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LB7DA2C567798081Adouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual274181.703266.2162%25500064387500.60822.5949%182.311467.0929%
Target2695.670163.7681%150000225000001.40543.7852%7.075565.1396%
Difference+5+176.0331+2.4481%+105000-16061250-0.7972-1.1903%+175.2359+1.9533%

Known prime factors:
No known factors for M21055579

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-11-16ANONYMOUSv4_computers2550006438750---0.608--2.595%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2001-04-21ANONYMOUSv4_computers21256--0.000--
2002-11-09Team Prime Ribv4_computers21266--0.701--
2015-04-09NRManual testing266267--0.710--
2017-05-04ramgeisManual testing267268--1.420--
2017-09-15ramgeisManual testing268269--2.839--
2017-09-15ramgeisManual testing269270--5.678--
2021-09-15SRBaseManual testing270271--11.36--
2021-10-01-Anonymous-Manual testing271272--22.71--
2021-11-19-Anonymous-Manual testing272273--45.43--
2021-12-23-Anonymous-Manual testing273274--90.86--


ECM factoring results:
No ECM results for M21055579


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
2003-12-23ANONYMOUSv4_computersB7DA2C567798081A14.92
2009-02-28shaneamyJerry-1B7DA2C567798081A14.92


PRP results:
No PRP results for M21055579


P-1 factor-bounds graph:
B1 = 255000, B2 = 6438750 (P-1 stage 2)
B1 = 255000 (P-1 stage 1)
104
105
106
104
105
106
107
TF factor-bounds graph:
274
273
272
271
270
269
268
267
266
256
this exponent TF target: 69
TF double-checked to: 67.9
250
260
270
280
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Last modified: 2023-10-02T12:12:48+00:00