is 2 1897121 - 1
has 571091 decimal digits
takes 0.103 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26831.418669.1176%200000000200880974580875.801021.3423%907.219675.7087%
Target2610.161965.5738%100001600000.00141.7268%0.163366.1683%
Difference+7+31.2567+3.5439%+199990000+200880814580+875.7996+19.6155%+907.0562+9.5404%

Known prime factors (9 factors, 396.0 bits, 0.02087448% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
189712111382727823.4403
3
-135.894e-138.723e-81.601e-7
1897121106238777926.66328
22 × 7
2008-07-15474.741e-123.275e-76.404e-7
189712149742512631032.2121311
3 × 19 × 23
2008-07-1519233.872e-101.512e-63.042e-6
1897121283809301611134.7247480
23 × 5 × 11 × 17
2008-07-1511171.953e-98.910e-71.761e-6
1897121373960491531135.1229856
27 × 7 × 11
2008-07-151281282.734e-91.007e-52.049e-5
1897121366841734679611445.0609668380
22 × 5 × 229 × 2111
2014-01-1422921114.257e-62.608e-53.666e-5
189712128454735755384011651.338749945200
24 × 52 × 19 × 101 × 977
2014-06-241019770.00031.170e-51.617e-5
189712113197454178372174878072270.161347828477423743
1051 × 330950026093
2020-09-071051330950026093241.721,418.42,649.1
18971211853109139457523979484412477.29448840035492135820
22 × 3 × 5 × 883 × 921857974559
2021-08-1888392185797455916,9723,950.97,379.1

502 Composite Factors:
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2016-03-15James HeinrichManual testing1000000030000000012-
skipped known factor: 11382727
skipped known factor: 106238777
skipped known factor: 4974251263
skipped known factor: 28380930161
skipped known factor: 37396049153
skipped known factor: 36684173467961
skipped known factor: 2845473575538401
--2.029--9.761%
2016-03-17alpertronManual testing30000000100000000012-
skipped known factor: 11382727
skipped known factor: 106238777
skipped known factor: 4974251263
skipped known factor: 28380930161
skipped known factor: 37396049153
skipped known factor: 36684173467961
skipped known factor: 2845473575538401
--6.517--12.041%
2016-03-17alpertronManual testing100000000300000000012-
skipped known factor: 11382727
skipped known factor: 106238777
skipped known factor: 4974251263
skipped known factor: 28380930161
skipped known factor: 37396049153
skipped known factor: 36684173467961
skipped known factor: 2845473575538401
--20.29--14.265%
2021-04-05Seth_TrManual testing20000000040200000000-
skipped known factor: 11382727
skipped known factor: 106238777
skipped known factor: 4974251263
skipped known factor: 28380930161
skipped known factor: 37396049153
skipped known factor: 36684173467961
skipped known factor: 2845473575538401
--187.2--18.802%
2021-12-20Seth_TrManual testing200000000200880974580-
skipped known factor: 11382727
skipped known factor: 106238777
skipped known factor: 4974251263
skipped known factor: 28380930161
skipped known factor: 37396049153
skipped known factor: 36684173467961
skipped known factor: 2845473575538401
--875.8--21.342%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-10-07nordisweet1650000000500000000027--26.77
2021-10-15nordisweet1640000000400000000065--21.41


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
2008-07-15J FeitsmaManual testing??26.66392.85604e-140.2196.08772e-14
2008-07-15J FeitsmaManual testing??34.724117.46814e-100.2191.59185e-9
2008-07-15J FeitsmaManual testing??35.122113.21705e-100.2196.85720e-10
2008-07-15J FeitsmaManual testing??32.212108.55833e-110.2191.82423e-10
2014-01-14TJAOIManual testing??45.060141.78617e-60.2193.80718e-6
2014-06-24TJAOIManual testing??51.338160.0000.2190.000
2022-09-29LordJuliusManual testing2126126.66394.74103e-120.2191.01056e-11
2022-09-29LordJuliusManual testing2126123.44085.89441e-130.2191.25641e-12
2022-09-29LordJuliusManual testing2126150.103169.68425e-50.2190.000
2022-09-29LordJuliusManual testing2126134.724111.95321e-90.2194.16330e-9
2022-09-29LordJuliusManual testing2126158.165180.0210.2090.043
2022-09-29LordJuliusManual testing2126135.122112.73449e-90.2195.82862e-9
2022-09-29LordJuliusManual testing2126132.212103.87181e-100.2198.25286e-10
2022-09-29LordJuliusManual testing2126155.652170.0040.2140.008
2022-09-29LordJuliusManual testing2126151.338160.0000.2190.001
2022-09-29LordJuliusManual testing2126145.060144.25686e-60.2199.07339e-6
2022-09-29LordJuliusManual testing2126158.563180.0390.2090.080
2022-09-29LordJuliusManual testing2126158.875180.0330.2090.067
2022-09-29LordJuliusManual testing261262--0.162--
2022-09-29LordJuliusManual testing262263--0.517--
2022-09-29LordJuliusManual testing263264--1.035--
2022-09-29LordJuliusManual testing264265--1.969--
2022-09-29LordJuliusManual testing265266--3.939--
2022-09-29LordJuliusManual testing266267--7.878--
2022-11-24LordJuliusManual testing267268--15.76--


ECM factoring results:
Total ECM effort:221.350 GHz-days
Estimated T-Level:29.476
DigitsB1CompleteFacMiss
201100055.4040.000%
25500008.1910.028%
302500000.89540.849%
3510000000.07592.773%
4030000000.00599.496%


ECM Summary

B1B2factorcurvesGHz-days
500005000000120.832
50000500000050.347
500006750000725.693
500006750000423.321
2500003825000010042.04
2500003852911610042.19
2500003873731610042.31
2500003874243510042.31
2500003875000010042.31


Lucas-Lehmer results:
No L-L results for M1897121


PRP results:
dateuseridcompidcofactorsres64PRP
2017-10-04Oliver KruseGTX-0
11382727
106238777
4974251263
28380930161
37396049153
36684173467961
2845473575538401
83517C25EF5D2DB1no
2017-10-05Oliver KruseManual testing
11382727
106238777
4974251263
28380930161
37396049153
36684173467961
2845473575538401
83517C25EF5D2D__no
2017-11-11kkmrkkblmbrbkc4.xlarge
11382727
106238777
4974251263
28380930161
37396049153
36684173467961
2845473575538401
83517C25EF5D2D__no
2020-09-07ATHec2-PRPCF
11382727
106238777
4974251263
28380930161
37396049153
36684173467961
2845473575538401
1319745417837217487807
4422A2AE3A1D4A8Dno
2021-08-18SRJ2877LTOS
11382727
106238777
4974251263
28380930161
37396049153
36684173467961
2845473575538401
1319745417837217487807
185310913945752397948441
4422A2AE3A1D4A8Dno


P-1 factor-bounds graph:
B1 = 200000000, B2 = 200880974580 (P-1 stage 2)
B1 = 200000000, B2 = 40200000000 (P-1 stage 2)
B1 = 100000000, B2 = 3000000000 (P-1 stage 2)
B1 = 200000000 (P-1 stage 1)
B1 = 100000000 (P-1 stage 1)
B1 = 30000000, B2 = 1000000000 (P-1 stage 2)
B1 = 30000000 (P-1 stage 1)
B1 = 10000000, B2 = 300000000 (P-1 stage 2)
B1 = 10000000 (P-1 stage 1)
100
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105
106
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109
100
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109
1010
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TF factor-bounds graph:
268
267
266
265
264
263
262
261
2
220
230
240
250
260
270
280
290
2100
Last modified: 2022-11-24T09:25:22+00:00