is 2 1861261 - 1
has 560296 decimal digits
takes 0.101 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L2FEFBEADDA05842Bdouble-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26832.023969.1176%25798892047387101.06938.4104%33.093371.7150%2.5973%
PrimeNet2570.010363.1579%90001600000.00143.0265%0.011764.2729%1.1150%
GPU722610.165065.5738%90001500000.00131.6330%0.166466.1359%0.5622%
Difference+7+31.8589+3.5439%+2570889+204588710+1.0680+6.7774%+32.9269+5.5790%+5.5790%

Known prime factors:
No known factors for M1861261

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2012-01-05T13:54:00markrtiny2750006000000---0.046--3.535%
2015-10-07T03:10:20Bruno Victal5820K-linux5000001500000012---0.101--4.609%
2016-09-14T01:57:19Jocelyn Larouchelow 4M5000003000000012---0.166--5.222%
2016-09-30T05:55:09Jocelyn Larouchelow 4M500000330000006---0.179--5.308%
2016-10-07T05:52:37Jocelyn Larouchelow 4M500000396000006---0.207--5.472%
2016-10-29T20:53:45Jocelyn Larouchelow 4M600000600000---0.047--1.923%
2016-12-19T18:36:36Jocelyn Larouchelow 4M720000720000---0.057--2.075%
2016-12-30T23:10:08Jocelyn Larouchelow 4M864000864000---0.068--2.234%
2017-01-14T05:24:36Jocelyn Larouchelow 4M10368001036800---0.082--2.399%
2017-02-12T18:28:06Jocelyn Larouchelow 4M12441601244160012---0.146--4.879%
2017-03-25T20:16:12Jocelyn Larouchelow 4M14929921492992012---0.175--5.142%
2017-03-29T03:10:19Jocelyn Larouchelow 4M17915901791590012---0.210--5.411%
2017-05-22T21:10:26Jocelyn Larouchelow 4M21499082149908012---0.252--5.686%
2017-06-14T03:17:00Jocelyn Larouchelow 4M25798894643800212---0.391--6.655%
2018-02-23T13:04:51Jocelyn Larouchelow 4M25798899287600412---0.590--7.472%
2018-09-17T11:34:54Jocelyn Larouchelow 4M257988918612610012---0.990--8.297%
2018-10-25T11:45:57Jocelyn LaroucheManual testing257988920473871012---1.069--8.410%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2003-01-09T00:00:00ANONYMOUSv4_computers21258--0.021--
2016-02-23T16:28:55Mark RoseManual testing258260--0.062--
2010-04-06T12:16:00Architects CubedManual testing260261--0.083--
2016-02-23T16:28:55Mark RoseManual testing261262--0.165--
2011-03-08T05:14:00GrunwalderGIMPManual testing21263--0.857--
2016-02-23T16:28:55Mark RoseManual testing262263--0.527--
2015-05-07T05:08:00snme2pm1Manual testing263264--1.055--
2015-05-07T05:08:00snme2pm1Manual testing264265--2.007--
2015-09-10T08:47:00ramgeisManual testing265266--4.015--
2018-05-14T16:20:06TJAOIManual testing266267--8.030--
2019-07-01T11:11:03TJAOIManual testing267268--16.06--


ECM factoring results:

Old Calculation Method

Total ECM effort:18.337 GHz-days
Estimated T-Level:24.500
DigitsB1CurvesCompleteFacMiss
2011000253 / 1002.5307.865%
2550000252 / 2800.90040.592%

New Calculation Method

Total ECM effort:18.337 GHz-days
Estimated T-Level:24.500
DigitsB1CompleteFacMiss
20110009.9990.005%
25500000.92939.489%
302500000.05994.242%
3510000000.00399.718%


ECM Summary

B1B2factorcurvesGHz-days
49000490000010.068
50000500000018112.53
50000545000070.502
500006600000534.136
50000675000070.552
51000510000010.071
74000740000010.102
75000750000010.104
1999001999000010.277


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-01-02T00:00:00ANONYMOUSv4_computers2FEFBEADDA05842B0.101
2015-07-16T04:00:00MadPooManual testing2FEFBEADDA05842B0.101


PRP results:
No PRP results for M1861261


P-1 factor-bounds graph:
B1 = 2579889, B2 = 204738710 (P-1 stage 2)
B1 = 2579889, B2 = 186126100 (P-1 stage 2)
B1 = 2579889, B2 = 92876004 (P-1 stage 2)
B1 = 2579889, B2 = 46438002 (P-1 stage 2)
B1 = 2149908, B2 = 21499080 (P-1 stage 2)
B1 = 1791590, B2 = 17915900 (P-1 stage 2)
B1 = 500000, B2 = 39600000 (P-1 stage 2)
B1 = 2579889 (P-1 stage 1)
B1 = 500000, B2 = 33000000 (P-1 stage 2)
B1 = 1492992, B2 = 14929920 (P-1 stage 2)
B1 = 2149908 (P-1 stage 1)
B1 = 500000, B2 = 30000000 (P-1 stage 2)
B1 = 1244160, B2 = 12441600 (P-1 stage 2)
B1 = 1791590 (P-1 stage 1)
B1 = 1492992 (P-1 stage 1)
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 1244160 (P-1 stage 1)
B1 = 1036800 (P-1 stage 1)
B1 = 864000 (P-1 stage 1)
B1 = 720000 (P-1 stage 1)
B1 = 600000 (P-1 stage 1)
B1 = 275000, B2 = 6000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
B1 = 275000 (P-1 stage 1)
104
105
106
107
104
105
106
107
108
109
TF factor-bounds graph:
268
267
266
265
264
263
262
261
260
258
250
260
270
280
290
2100
Last modified: 2021-08-20T12:35:49+00:00