is 2 720221 - 1
has 216809 decimal digits
takes 0.014 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-L2CED30144D30186Edouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26882.759170.5882%2400000012000000002.550511.3241%85.309773.9188%
Target2440.000054.5455%120004500000.001016.5537%0.001062.0699%
Difference+24+82.7591+16.0428%+23988000+1199550000+2.5495-5.2297%+85.3086+11.8490%

Known prime factors (1 factor, 125.2 bits, 0.01738043% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
7202214810380185659554504451353815940860641738125.17733395167494835297113326005600648
23 × 1049 × 2027 × 11443 × 56333 × 1903073 × 1600317581
2023-01-27190307316003175812.124e+112.57714.7160

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2002-01-02ANONYMOUSv4_computers2000200000---0.000--0.158%
2002-01-28ANONYMOUSv4_computers4096409600---0.001--0.349%
2002-03-16ANONYMOUSv4_computers8192819200---0.002--0.646%
2002-05-11ANONYMOUSv4_computers163841638400---0.003--1.072%
2002-07-14ANONYMOUSv4_computers327683276800---0.006--1.636%
2002-11-09ANONYMOUSv4_computers655376553700---0.012--2.337%
2003-06-17ANONYMOUSv4_computers13107213107200---0.024--3.164%
2008-11-29Jayson Kingatlas5000000100000000---0.295--7.223%
2016-05-24mikrS05824000000120000000012---2.551--11.324%
2023-01-27Jocelyn LaroucheManual testing1000000492981489038125.1777.8060.02915.6110.110%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-12-15ANONYMOUSv4_computers253254--0.002--
2000-05-24ANONYMOUSv4_computers21255--0.007--
2000-05-31ANONYMOUSv4_computers21255--0.007--
2001-04-01ANONYMOUSv4_computers21256--0.013--
2001-10-20ANONYMOUSv4_computers21257--0.027--
2003-09-21ANONYMOUSv4_computers21258--0.053--
2008-10-11Sturle Sundekinner.ifi258259--0.053--
2008-10-11Sturle Sundekinner.ifi259260--0.107--
2010-06-17Architects Cubeda3_ss260261--0.213--
2015-03-01NRManual testing261262--0.427--
2015-10-14Gordon SpenceManual testing262263--1.363--
2015-10-14Gordon SpenceManual testing263264--2.726--
2016-04-26lycornManual testing264265--5.188--
2017-07-20Smok_bmvManual testing265266--10.38--
2020-05-08Gordon SpenceManual testing266267--20.75--
2022-03-26Gordon SpenceManual testing267268--41.50--


ECM factoring results:
Total ECM effort:17.323 GHz-days
Estimated T-Level:26.066
DigitsB1CompleteFacMiss
201100019.5600.000%
25500002.3589.464%
302500000.21380.797%
3510000000.01698.444%


ECM Summary

B1B2factorcurvesGHz-days
5000050000002806.332
250000250000008910.06
2500003725000070.928


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1997-01-01Ken Kriesel2CED30144D30186E0.014
2002-10-07ANONYMOUSv4_computers2CED30144D30186E0.014
2015-04-11MadPooManual testing2CED30144D30186E0.014


PRP results:
dateuseridcompidcofactorsres64PRP
2023-01-28Kevin_9611
48103801856595545044513538159408606417
BE447A39ED98D58Dno


P-1 factor-bounds graph:
B1 = 1000000, B2 = 4929814890 (P-1 stage 2)
B1 = 24000000, B2 = 1200000000 (P-1 stage 2)
B1 = 24000000 (P-1 stage 1)
B1 = 5000000, B2 = 100000000 (P-1 stage 2)
B1 = 5000000 (P-1 stage 1)
B1 = 1000000 (P-1 stage 1)
B1 = 131072, B2 = 13107200 (P-1 stage 2)
B1 = 65537, B2 = 6553700 (P-1 stage 2)
B1 = 32768, B2 = 3276800 (P-1 stage 2)
B1 = 131072 (P-1 stage 1)
B1 = 16384, B2 = 1638400 (P-1 stage 2)
B1 = 65537 (P-1 stage 1)
B1 = 8192, B2 = 819200 (P-1 stage 2)
B1 = 32768 (P-1 stage 1)
B1 = 4096, B2 = 409600 (P-1 stage 2)
B1 = 16384 (P-1 stage 1)
B1 = 2000, B2 = 200000 (P-1 stage 2)
B1 = 8192 (P-1 stage 1)
B1 = 4096 (P-1 stage 1)
B1 = 2000 (P-1 stage 1)
102
103
104
105
106
107
108
102
103
104
105
106
107
108
109
1010
TF factor-bounds graph:
268
267
266
265
264
263
262
261
260
259
258
257
256
255
254
this exponent TF target: 44
TF double-checked to: 67.7
ECM T-Level=26.07 ~= 70-bit
250
260
270
280
290
2100
2110
2120
2130
Last modified: 2023-03-25T13:08:14+00:00