is 2 121997 - 1
has 36725 decimal digits
takes 0.000 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L2519F39621A1D2D3double-checked
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual267243.562774.6269%10000000020000000000.770511.8958%244.333277.6452%3.0183%
PrimeNet2400.000057.5000%1300240000.00009.1616%0.000061.3937%3.8937%
GPU722440.000061.3636%2000340000.00005.8912%0.000063.6398%2.2762%
Difference+23+243.5627+13.2632%+99998000+1999966000+0.7705+6.0045%+244.3332+14.0054%+14.0054%

Known prime factors (2 factors, 171.6 bits, 0.14068551% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1219972154383364782110451594172477.512882965714231542764
22 × 3 × 41 × 653561 × 2745949897
2015-02-136535612745949897349,9470.56881.0579
121997215322258810466155777238771032994.12088248997438652653662483
32 × 4042391 × 4851493 × 499981049
2008-12-2148514934999810493.974e+100.12050.1926

1 Composite Factors:
exponentprime factorscomposite factordigitsbits*
12199746388669244857650416804613329542429144312099511289
51
52171.632
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2001-04-29T00:00:00ANONYMOUSv4_computers10000010000000---0.002--2.431%
2002-06-02T00:00:00ANONYMOUSv4_computers327683276800---0.001--1.363%
2002-07-20T00:00:00ANONYMOUSv4_computers655366553600---0.002--1.987%
2003-02-09T00:00:00ANONYMOUSv4_computers13107213107200---0.003--2.739%
2003-09-29T00:00:00ANONYMOUSv4_computers26214426214400---0.006--3.608%
2017-02-23T17:19:53kkmrkkblmbrbkManual testing100000000200000000012-
skipped known factor: 21532225881046615577723877103
--0.771--11.896%


Trial Factoring results:
 BitsFactorGHz-Daysworth
dateuseridcompidfromtofactorbits*digitsspentsaved
1999-09-22T00:00:00ANONYMOUSv4_computers252253--0.005--
2000-04-19T00:00:00ANONYMOUSv4_computers21254--0.020--
2022-03-07T03:13:36LordJuliusManual testing254255--0.020--
2000-12-21T00:00:00ANONYMOUSv4_computers21256--0.079--
2002-06-09T00:00:00ANONYMOUSv4_computers21257--0.157--


ECM factoring results:

Old Calculation Method

Total ECM effort:12.116 GHz-days
Estimated T-Level:30.201
DigitsB1CurvesCompleteFacMiss
2011000896 / 1008.9600.012%
2550000896 / 2803.2004.053%
30250000647 / 6401.01136.359%
35100000063 / 15660.04096.056%

New Calculation Method

Total ECM effort:12.116 GHz-days
Estimated T-Level:30.201
DigitsB1CompleteFacMiss
201100073.1680.000%
255000011.2110.001%
302500001.28927.558%
3510000000.12088.694%
4030000000.00999.059%


ECM Summary

B1B2factorcurvesGHz-days
10.00000e+0
10.00000e+0
5000050000002490.681
250000250000005847.988
1000000100000000633.447


Lucas-Lehmer results:
No L-L results for M121997


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-21T21:33:00Oliver KruseDoppelherz
215438336478211045159417
21532225881046615577723877103
594C00D0CBCB416Ano
2017-09-22T10:00:57Oliver KruseManual testing
215438336478211045159417
21532225881046615577723877103
594C00D0CBCB416Ano
2017-10-09T03:09:14Chang Chia-Tchehomura594C00D0CBCB41__?
2017-10-13T19:02:03kkmrkkblmbrbkManual testing
215438336478211045159417
21532225881046615577723877103
594C00D0CBCB41__no
2020-04-17T15:34:07Oliver KruseAddPrpType5
215438336478211045159417
21532225881046615577723877103
B238F73EADEA51__no


P-1 factor-bounds graph:
B1 = 100000000, B2 = 2000000000 (P-1 stage 2)
B1 = 100000000 (P-1 stage 1)
B1 = 262144, B2 = 26214400 (P-1 stage 2)
B1 = 131072, B2 = 13107200 (P-1 stage 2)
B1 = 100000, B2 = 10000000 (P-1 stage 2)
B1 = 65536, B2 = 6553600 (P-1 stage 2)
B1 = 262144 (P-1 stage 1)
B1 = 32768, B2 = 3276800 (P-1 stage 2)
B1 = 131072 (P-1 stage 1)
B1 = 100000 (P-1 stage 1)
B1 = 65536 (P-1 stage 1)
B1 = 32768 (P-1 stage 1)
103
104
105
106
107
108
103
104
105
106
107
108
109
1010
TF factor-bounds graph:
267
257
256
255
254
253
250
260
270
280
290
2100
Last modified: 2022-03-07T03:13:36+00:00