is 2 255239 - 1
has 76835 decimal digits
takes 0.001 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LB45DCC8787ED449Adouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual270936.183974.2857%100000000020145430890585089,307.911227.9451%90,244.095181.4716%
Target2440.000059.0909%45001100000.000110.1928%0.000163.2607%
Difference+26+936.1838+15.1948%+999995500+201454308795850+89,307.9111+17.7523%+90,244.0950+18.2109%

Known prime factors:
No known factors for M255239

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2000-12-14ANONYMOUSv4_computers950003800000---0.002--1.513%
2001-06-17ANONYMOUSv4_computers10000010000000---0.005--1.893%
2002-06-02ANONYMOUSv4_computers327683276800---0.002--1.020%
2002-08-10ANONYMOUSv4_computers655366553600---0.003--1.526%
2003-03-07ANONYMOUSv4_computers13107213107200---0.007--2.152%
2003-11-08ANONYMOUSv4_computers26214426214400---0.014--2.892%
2011-02-07Jocelyn LaroucheManual testing20000002000000---0.016--1.897%
2012-02-26Jocelyn LaroucheManual testing24394532439453---0.020--2.050%
2013-10-14David Campeaui5-2500k256000071680000---0.051--4.886%
2015-01-16thelegendarymudkipi5-4670k10000000250000000---0.188--6.782%
2016-05-13mognutsManual testing285471350---5.35832e-5--0.074%
2021-12-04Seth_TrManual testing120000000120000000---0.976--6.340%
2021-12-05Seth_TrManual testing12000000057783635910---26.54--15.133%
2022-03-31Anton RepkoManual testing1000000000201454308905850---89,308--27.945%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2023-01-27masserManual testing3000000099000000027--0.788
2023-02-05masserManual testing3000000096000000013411--0.775
2023-02-11masserManual testing3000000099000000065--0.788


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-11-24ANONYMOUSv4_computers252253--0.002--
2000-04-27ANONYMOUSv4_computers21254--0.009--
2000-12-14ANONYMOUSv4_computers21255--0.019--
2001-02-18ANONYMOUSv4_computers21256--0.038--
2002-03-16ANONYMOUSv4_computers21257--0.075--
2004-02-14ANONYMOUSv4_computers21258--0.150--
2009-01-01Sturle Sundegobi.ifi258259--0.150--
2009-01-25Sturle Sundeginjtje.ifi259260--0.301--
2013-07-25Sid & AndyBuzz260261--0.602--
2015-08-25NRManual testing261262--1.204--
2016-01-30Gordon SpenceManual testing262263--3.846--
2016-01-30Gordon SpenceManual testing263264--7.692--
2018-03-15Gordon SpenceManual testing264265--14.64--
2020-01-01Gordon SpenceManual testing265266--29.28--
2022-03-12Anton RepkoManual testing266270--878.3--


ECM factoring results:
Total ECM effort:878.510 GHz-days
Estimated T-Level:34.540
DigitsB1CompleteFacMiss
2011000221.2020.000%
255000047.5950.000%
302500007.3690.063%
3510000000.90840.333%
4030000000.09391.163%
45110000000.00899.208%


ECM Summary

B1B2factorcurvesGHz-days
5000050000003071.837
2500002500000058017.35
100000010000000010011.97
10000002842011315700847.4


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1997-01-01Brian J. BeesleysamsonB45DCC8787ED449A0.001
2001-10-13ANONYMOUSv4_computersB45DCC8787ED449A0.001


PRP results:
No PRP results for M255239


P-1 factor-bounds graph:
B1 = 1000000000, B2 = 201454308905850 (P-1 stage 2)
B1 = 120000000, B2 = 57783635910 (P-1 stage 2)
B1 = 1000000000 (P-1 stage 1)
B1 = 120000000 (P-1 stage 1)
B1 = 10000000, B2 = 250000000 (P-1 stage 2)
B1 = 10000000 (P-1 stage 1)
B1 = 2560000, B2 = 71680000 (P-1 stage 2)
B1 = 2560000 (P-1 stage 1)
B1 = 2439453 (P-1 stage 1)
B1 = 2000000 (P-1 stage 1)
B1 = 262144, B2 = 26214400 (P-1 stage 2)
B1 = 131072, B2 = 13107200 (P-1 stage 2)
B1 = 100000, B2 = 10000000 (P-1 stage 2)
B1 = 65536, B2 = 6553600 (P-1 stage 2)
B1 = 95000, B2 = 3800000 (P-1 stage 2)
B1 = 262144 (P-1 stage 1)
B1 = 32768, B2 = 3276800 (P-1 stage 2)
B1 = 131072 (P-1 stage 1)
B1 = 100000 (P-1 stage 1)
B1 = 95000 (P-1 stage 1)
B1 = 65536 (P-1 stage 1)
B1 = 32768 (P-1 stage 1)
B1 = 2854, B2 = 71350 (P-1 stage 2)
B1 = 2854 (P-1 stage 1)
102
103
104
105
106
107
108
109
102
103
104
105
106
107
108
109
1010
1011
1012
1013
1014
1015
TF factor-bounds graph:
270
266
265
264
263
262
261
260
259
258
257
256
255
254
253
this exponent TF target: 44
TF double-checked to: 67.7
ECM T-Level=34.54 ~= 98-bit
250
260
270
280
290
2100
Last modified: 2023-03-23T17:39:31+00:00