is 2 2528893 - 1
has 761273 decimal digits
takes 0.175 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
factored, 0 LL tests remaining
ResidueStatus
L-LD50F76E10362249Fdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26947.209168.1159%5000000864646965047.854013.0599%95.063272.2800%
Target2630.631165.0794%110001800000.00201.4349%0.633165.5804%
Difference+6+46.5780+3.0366%+4989000+8646289650+47.8520+11.6251%+94.4300+6.6996%

Known prime factors (1 factor, 127.2 bits, 0.00503147% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
252889320101158098729826090738476959544292490339127.24139742998416164357469332385671407
3 × 7 × 1613 × 208729 × 360277 × 3397967 × 4591646869
2023-02-06339796745916468695.850e+1025.48346.992

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2011-01-06Jocelyn LaroucheManual testing5000050000---0.005--0.453%
2011-03-17James HeinrichWHS3000008000000---0.072--3.566%
2018-01-03Jocelyn Larouchelow 4M25288931600000012---0.328--5.114%
2022-09-15seatseadt30400007925689200---43.72--12.408%
2023-02-06Architects Cubedgpu72ng5000000864646965039127.24147.850.35195.7113.060%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-08-16ANONYMOUSv4_computers21259--0.030--
2016-02-23Mark RoseManual testing259260--0.030--
2009-01-31Sturle Sundegehry.ifi260261--0.061--
2012-06-14Sebastian HornbostelManual testing261262--0.121--
2013-01-23dbaughManual testing262263--0.388--
2015-02-23VictordeHollanderManual testing263264--0.776--
2015-02-23VictordeHollanderManual testing264265--1.477--
2015-11-08ramgeisManual testing265266--2.955--
2017-08-08Gordon SpenceManual testing266267--5.910--
2019-04-15TJAOIManual testing267268--11.82--
2021-06-10TJAOIManual testing268269--23.64--


ECM factoring results:
Total ECM effort:16.543 GHz-days
Estimated T-Level:23.159
DigitsB1CompleteFacMiss
20110006.8210.109%
25500000.63253.161%
302500000.04096.087%
3510000000.00299.813%


ECM Summary

B1B2factorcurvesGHz-days
50000500000014012.89
50000515000070.653
50000675000070.740
50000692844070.750
500007000000141.507


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1997-01-01Michael B. ClarkD50F76E10362249F0.175
2015-11-14MadPooManual testingD50F76E10362249F0.175


PRP results:
dateuseridcompidcofactorsres64PRP
2023-02-08LordJuliusWhiteBox
201011580987298260907384769595442924903
45BF8172DD2058CEno


P-1 factor-bounds graph:
B1 = 5000000, B2 = 8646469650 (P-1 stage 2)
B1 = 3040000, B2 = 7925689200 (P-1 stage 2)
B1 = 5000000 (P-1 stage 1)
B1 = 2528893, B2 = 16000000 (P-1 stage 2)
B1 = 3040000 (P-1 stage 1)
B1 = 2528893 (P-1 stage 1)
B1 = 300000, B2 = 8000000 (P-1 stage 2)
B1 = 300000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
103
104
105
106
107
103
104
105
106
107
108
109
1010
TF factor-bounds graph:
269
268
267
266
265
264
263
262
261
260
259
this exponent TF target: 63
TF double-checked to: 67.7
ECM T-Level=23.16 ~= 60-bit
250
260
270
280
290
2100
2110
2120
2130
Last modified: 2023-03-25T13:08:14+00:00