is 2 2557171 - 1
has 769786 decimal digits
takes 0.177 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-LA4BDC578A751B0F0double-checked
PRP17A0D65B37A4EE23verified PRP

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26946.687168.1159%32000001120000000.91807.4456%47.605170.4899%2.3740%
PrimeNet2590.030062.7119%110002000000.00212.6866%0.032263.7137%1.0018%
GPU722630.624165.0794%120001800000.00211.4788%0.626365.5958%0.5164%
Difference+6+46.0629+3.0366%+3188000+111820000+0.9159+5.9667%+46.9788+4.8941%+4.8941%

Known prime factors (1 factor, 80.2 bits, 0.00313590% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
255717113794604933821759676173132580.190269723943643615536
24 × 3 × 47 × 389 × 307348292179
2021-06-15389307348292179149,9781,684.13,145.5

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2003-10-23T00:00:00ANONYMOUSv4_computers2048204800---0.001--0.191%
2003-11-08T00:00:00Team Prime Ribv4_computers15000198750---0.003--0.645%
2010-12-21T01:09:00Jocelyn LaroucheManual testing2000020000---0.002--0.222%
2011-01-03T14:35:00Jocelyn LaroucheManual testing3000030000---0.003--0.311%
2011-01-09T14:30:00Jocelyn LaroucheManual testing5000050000---0.005--0.454%
2011-04-11T01:56:00James HeinrichWHS1750004068750---0.039--2.831%
2016-04-12T01:03:18mikrMSI320000011200000012---0.918--7.446%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-03-15T00:00:00ANONYMOUSv4_computers21259--0.030--
2016-02-23T16:29:16Mark RoseManual testing259260--0.030--
2009-02-01T16:50:00Sturle Sundekorsmo.ifi260261--0.060--
2011-12-26T23:23:00c10ck3rManual testing261262--0.120--
2013-01-14T11:55:00dbaughManual testing262263--0.384--
2015-02-23T17:24:00VictordeHollanderManual testing263264--0.768--
2015-02-23T17:24:00VictordeHollanderManual testing264265--1.461--
2015-11-08T05:40:29omylistManual testing265266--2.922--
2017-08-10T07:53:55Gordon SpenceManual testing266267--5.845--
2019-04-29T13:20:20TJAOIManual testing267268--11.69--
2021-05-27T10:38:49TJAOIManual testing268269--23.38--


ECM factoring results:

Old Calculation Method

Total ECM effort:11.346 GHz-days
Estimated T-Level:22.196
DigitsB1CurvesCompleteFacMiss
2011000123 / 1001.23029.049%
2550000123 / 2800.43964.399%

New Calculation Method

Total ECM effort:11.346 GHz-days
Estimated T-Level:22.196
DigitsB1CompleteFacMiss
20110003.9681.892%
25500000.35969.865%
302500000.02297.816%
3510000000.00199.899%


ECM Summary

B1B2factorcurvesGHz-days
50000500000011610.70
50000500000070.646


Lucas-Lehmer results:
dateuseridcompidres64spent (GHz-days)
1999-04-13T00:00:00ANONYMOUSv4_computersA4BDC578A751B0F00.177
2018-06-13T02:26:20kkmrkkblmbrbkoldA4BDC578A751B0F00.177


PRP results:
dateuseridcompidcofactorsres64PRP
2021-06-16T13:39:58mrhlanai
1379460493382175967617313
17A0D65B37A4EE23no


P-1 factor-bounds graph:
B1 = 3200000, B2 = 112000000 (P-1 stage 2)
B1 = 3200000 (P-1 stage 1)
B1 = 175000, B2 = 4068750 (P-1 stage 2)
B1 = 175000 (P-1 stage 1)
B1 = 50000 (P-1 stage 1)
B1 = 30000 (P-1 stage 1)
B1 = 15000, B2 = 198750 (P-1 stage 2)
B1 = 20000 (P-1 stage 1)
B1 = 15000 (P-1 stage 1)
B1 = 2048, B2 = 204800 (P-1 stage 2)
B1 = 2048 (P-1 stage 1)
101
102
103
104
105
106
107
101
102
103
104
105
106
107
108
109
1010
1011
1012
TF factor-bounds graph:
269
268
267
266
265
264
263
262
261
260
259
250
260
270
280
290
2100
Last modified: 2021-06-16T13:39:58+00:00