is 2 2163923 - 1
has 651406 decimal digits
takes 0.142 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LE237391CC9A506A7double-checked
PRP81FD2CC96337024Everified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26827.544867.6471%50000002000000001.48968.9433%29.034470.5405%2.8934%
PrimeNet2580.017762.0690%100001800000.00182.8544%0.019663.1517%1.0827%
GPU722620.283964.5161%100001600000.00171.5198%0.285665.0554%0.5393%
Difference+6+27.2609+3.1309%+4990000+199840000+1.4878+7.4235%+28.7487+5.4851%+5.4851%

Known prime factors (1 factor, 84.0 bits, 0.00388377% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
2163923199116635732591570277706792684.0424600825346664173593
97 × 47431189140867769
2021-03-0697474311891408677692,732,660246,369,454460,149,531

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-02-09T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.225%
2003-02-24T00:00:00ANONYMOUSv4_computers4096409600---0.002--0.463%
2016-09-11T16:07:10Jocelyn Larouchelow 4M1815001441792012---0.091--4.000%
2017-05-13T16:00:11Jocelyn Larouchelow 4M36300036300006---0.052--3.342%
2017-06-10T03:57:30Jocelyn Larouchelow 4M43560043560006---0.062--3.563%
2017-06-28T04:14:44Jocelyn Larouchelow 4M52272052272006---0.074--3.791%
2017-08-22T09:50:07Jocelyn Larouchelow 4M627264627264012---0.089--4.025%
2017-08-24T01:00:12Jocelyn Larouchelow 4M752716752716012---0.107--4.267%
2019-10-23T17:23:09mikrMSI500000020000000012---1.490--8.943%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2003-03-27T00:00:00ANONYMOUSv4_computers21259--0.035--
2016-02-23T16:29:07Mark RoseManual testing259260--0.035--
2009-01-04T23:51:00Sturle Sundegoober.ifi260261--0.071--
2009-01-08T02:19:00Sturle Sundegoscha.ifi261262--0.142--
2013-01-23T08:20:00dbaughManual testing262263--0.454--
2015-03-25T10:09:00VictordeHollanderManual testing263264--0.907--
2015-03-25T10:09:00VictordeHollanderManual testing264265--1.727--
2015-12-30T18:01:38ramgeisManual testing265266--3.453--
2016-11-11T01:20:36Gordon SpenceManual testing266267--6.907--
2019-05-13T13:38:17TJAOIManual testing267268--13.81--


ECM factoring results:

Old Calculation Method

Total ECM effort:13.412 GHz-days
Estimated T-Level:22.786
DigitsB1CurvesCompleteFacMiss
2011000156 / 1001.56020.849%
2550000156 / 2800.55757.227%

New Calculation Method

Total ECM effort:13.412 GHz-days
Estimated T-Level:22.786
DigitsB1CompleteFacMiss
20110005.0480.642%
25500000.45763.346%
302500000.02897.227%
3510000000.00199.871%


ECM Summary

B1B2factorcurvesGHz-days
50000500000014312.22
50000500000060.513
50000675000070.684


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1998-04-11T00:00:00ANONYMOUSv4_computersE237391CC9A506A70.142
1999-02-21T00:00:00Ethan O'Connorv4_computersE237391CC9A506A70.142


PRP results:
dateuseridcompidcofactorsres64PRP
2021-03-06T15:17:07riccardo ubertiNomad2C
19911663573259157027770679
81FD2CC96337024Eno


P-1 factor-bounds graph:
B1 = 5000000, B2 = 200000000 (P-1 stage 2)
B1 = 5000000 (P-1 stage 1)
B1 = 752716, B2 = 7527160 (P-1 stage 2)
B1 = 181500, B2 = 14417920 (P-1 stage 2)
B1 = 627264, B2 = 6272640 (P-1 stage 2)
B1 = 522720, B2 = 5227200 (P-1 stage 2)
B1 = 752716 (P-1 stage 1)
B1 = 435600, B2 = 4356000 (P-1 stage 2)
B1 = 627264 (P-1 stage 1)
B1 = 363000, B2 = 3630000 (P-1 stage 2)
B1 = 522720 (P-1 stage 1)
B1 = 435600 (P-1 stage 1)
B1 = 363000 (P-1 stage 1)
B1 = 181500 (P-1 stage 1)
B1 = 4096, B2 = 409600 (P-1 stage 2)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 4096 (P-1 stage 1)
B1 = 2048 (P-1 stage 1)
100
101
102
103
104
105
106
107
100
101
102
103
104
105
106
107
108
109
1010
1011
1012
1013
1014
1015
1016
1017
TF factor-bounds graph:
268
267
266
265
264
263
262
261
260
259
250
260
270
280
290
2100
Last modified: 2021-03-06T15:17:07+00:00