is 2 254941 - 1
has 76745 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-LB91A6F9F569E303Bdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual270937.278274.2857%100000000020289610196856089,947.026027.9529%90,884.304281.4736%
Target2440.000059.0909%45001100000.000110.1909%0.000163.2599%
Difference+26+937.2782+15.1948%+999995500+202896101858560+89,947.0260+17.7620%+90,884.3041+18.2137%

Known prime factors:
No known factors for M254941

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2000-12-07ANONYMOUSv4_computers950003800000---0.002--1.512%
2001-06-17ANONYMOUSv4_computers10000010000000---0.005--1.893%
2002-06-02ANONYMOUSv4_computers327683276800---0.002--1.020%
2002-08-10ANONYMOUSv4_computers655366553600---0.003--1.525%
2003-03-07ANONYMOUSv4_computers13107213107200---0.007--2.152%
2003-11-08ANONYMOUSv4_computers26214426214400---0.014--2.891%
2011-02-07Jocelyn LaroucheManual testing20000002000000---0.016--1.897%
2012-02-26Jocelyn LaroucheManual testing24431512443151---0.020--2.051%
2013-10-14David Campeaui5-2500k256000071680000---0.051--4.885%
2015-01-16thelegendarymudkipi5-4670k10000000250000000---0.188--6.781%
2016-05-13mognutsManual testing285171275---5.35269e-5--0.074%
2021-12-05Seth_TrManual testing120000000120000000---0.976--6.339%
2021-12-05Seth_TrManual testing12000000057783635910---26.54--15.132%
2022-03-09-Anonymous-T58101000000000202896101968560---89,947--27.953%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2023-01-27masserManual testing3000000099000000027--0.788
2023-02-05masserManual testing3000000096000000011713--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--
2000-12-07ANONYMOUSv4_computers21255--0.019--
2001-02-18ANONYMOUSv4_computers21256--0.038--
2002-03-16ANONYMOUSv4_computers21257--0.075--
2004-02-14ANONYMOUSv4_computers21258--0.151--
2009-01-01Sturle Sundegobi.ifi258259--0.151--
2009-01-24Sturle Sundeginjtje.ifi259260--0.301--
2013-07-24Sid & AndyBuzz260261--0.602--
2015-08-25NRManual testing261262--1.205--
2016-01-30Gordon SpenceManual testing262263--3.851--
2016-01-30Gordon SpenceManual testing263264--7.701--
2018-03-15Gordon SpenceManual testing264265--14.66--
2020-01-01Gordon SpenceManual testing265266--29.31--
2022-02-06Anton RepkoManual testing266270--879.3--


ECM factoring results:
Total ECM effort:189.071 GHz-days
Estimated T-Level:34.957
DigitsB1CompleteFacMiss
2011000300.6180.000%
255000056.5690.000%
302500008.2920.025%
3510000000.99137.105%
4030000000.09890.634%
45110000000.00899.181%


ECM Summary

B1B2factorcurvesGHz-days
5000050000002801.675
2500002500000058517.50
10000001000000001,420169.9


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1997-01-01Brian J. BeesleysamsonB91A6F9F569E303B0.001
2001-10-13ANONYMOUSv4_computersB91A6F9F569E303B0.001


PRP results:
No PRP results for M254941


P-1 factor-bounds graph:
B1 = 1000000000, B2 = 202896101968560 (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 = 2443151 (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 = 2851, B2 = 71275 (P-1 stage 2)
B1 = 2851 (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: 67.8
ECM T-Level=34.96 ~= 100-bit
250
260
270
280
290
2100
Last modified: 2023-04-26T21:34:10+00:00