is 2 803251 - 1
has 241803 decimal digits
takes 0.016 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LA8B5624B8D87B486double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual270297.479471.4286%8027770501024934410790.739716.2449%1,088.219176.0700%
Target2440.000054.5455%1300025000000.004317.1263%0.004362.3301%
Difference+26+297.4794+16.8831%+8014770+501022434410+790.7354-0.8814%+1,088.2148+13.7398%

Known prime factors:
No known factors for M803251

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2002-01-02ANONYMOUSv4_computers2000200000---0.000--0.105%
2002-02-10ANONYMOUSv4_computers4096409600---0.001--0.243%
2002-03-31ANONYMOUSv4_computers8192819200---0.002--0.469%
2002-05-11ANONYMOUSv4_computers163841638400---0.003--0.805%
2002-06-02ANONYMOUSv4_computers327683276800---0.006--1.263%
2002-11-16ANONYMOUSv4_computers655376553700---0.012--1.849%
2003-07-06ANONYMOUSv4_computers13107213107200---0.024--2.558%
2012-08-01Jocelyn LaroucheManual testing16065021606502---0.047--2.037%
2013-10-25David Campeaui5-2500k165000056100000---0.134--5.069%
2015-11-24Sid & AndyWoody803251024097530012---0.600--7.410%
2022-04-03lycorncolab_A8027770501024934410---790.7--16.245%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-09-13gLaussManual testing750000058500000027--1.223
2023-09-21masserManual testing1000000079000000010747--1.646
2023-09-28masserManual testing1000000079000000065--1.646


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2000-07-17ANONYMOUSv4_computers21255--0.006--
2000-12-21ANONYMOUSv4_computers21256--0.012--
2001-09-30ANONYMOUSv4_computers21257--0.024--
2003-08-25ANONYMOUSv4_computers21258--0.048--
2008-10-12Sturle Sundescarpia.ifi258259--0.048--
2008-10-12Sturle Sundescarpia.ifi259260--0.096--
2010-05-25Architects Cubedm1_tt260261--0.191--
2015-01-16snme2pm1G1261262--0.382--
2015-09-26Gordon SpenceManual testing262263--1.222--
2015-09-26Gordon SpenceManual testing263264--2.444--
2016-03-01lycornManual testing264265--4.652--
2017-06-16Smok_bmvManual testing265266--9.303--
2017-06-16Smok_bmvManual testing266267--18.61--
2017-06-16Smok_bmvManual testing267268--37.21--
2019-11-07YxinityManual testing268269--74.42--
2019-11-09YxinityManual testing269270--148.8--


ECM factoring results:
Total ECM effort:1,650.341 GHz-days
Estimated T-Level:28.145
DigitsB1CompleteFacMiss
201100041.0100.000%
25500006.0050.247%
302500000.62953.313%
3510000000.05294.921%
4030000000.00499.647%


ECM Summary

B1B2factorcurvesGHz-days
5000050000003437.838
25000025000000313.542
35000049621119242001,639


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1997-01-01Dieter StahelA8B5624B8D87B4860.016
2015-04-11MadPooManual testingA8B5624B8D87B4860.016


PRP results:
No PRP results for M803251


P-1 factor-bounds graph:
B1 = 8027770, B2 = 501024934410 (P-1 stage 2)
B1 = 8032510, B2 = 240975300 (P-1 stage 2)
B1 = 8032510 (P-1 stage 1)
B1 = 8027770 (P-1 stage 1)
B1 = 1650000, B2 = 56100000 (P-1 stage 2)
B1 = 1650000 (P-1 stage 1)
B1 = 1606502 (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)
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1010
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TF factor-bounds graph:
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265
264
263
262
261
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255
this exponent TF target: 44
TF double-checked to: 67.9
ECM T-Level=28.14 ~= 77-bit
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Last modified: 2023-10-02T12:12:48+00:00