is 2 1918351 - 1
has 577482 decimal digits
takes 0.104 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
-unknown- primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26715.489368.6567%1000000710000000.37877.1688%15.868070.9037%2.2469%
PrimeNet2570.010063.1579%90001700000.00143.0923%0.011464.2972%1.1393%
GPU722610.160165.5738%100001700000.00151.7612%0.161666.1801%0.6063%
Difference+6+15.3292+3.0829%+990000+70830000+0.3772+5.4076%+15.7064+4.7236%+4.7236%

Known prime factors (3 factors, 166.8 bits, 0.00869415% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1918351200582780571134.2235228
22 × 1307
-413071.350e-95.899e-61.044e-5
1918351140511075990564840172063.6073662287975208
23 × 17 × 983 × 27394291
2015-10-01983273942911.79070.11750.2193
19183515715945714376096990392168.954148980705678369
32 × 17 × 1907 × 510608339
2020-10-31190751060833961.8902.18854.0872

4 Composite Factors:
exponentprime factorscomposite factordigitsbits*
19183512818410232307006272617623149693097.831
19183511146520284976732557076434768722332103.177
1918351803153682630643195405318555804088375966340132.561
191835116109879888708972442194864408980075862533601461479
1
51166.784
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2015-10-01T12:05:46alpertronManual testing50000015000000122063.6070.1010.2080.2035.097%
2021-04-07T21:57:26Dylan Delgadodesktoplinux100000071000000-
skipped known factor: 20058278057
skipped known factor: 14051107599056484017
--0.379--7.169%


Trial Factoring results:
No TF results for M1918351


ECM factoring results:

Old Calculation Method

Total ECM effort:20.483 GHz-days
Estimated T-Level:24.732
DigitsB1CurvesCompleteFacMiss
2011000265 / 1002.6506.972%
2550000265 / 2800.94638.747%

New Calculation Method

Total ECM effort:20.483 GHz-days
Estimated T-Level:24.732
DigitsB1CompleteFacMiss
201100010.9380.002%
25500001.00736.545%
302500000.06493.810%
3510000000.00399.700%


ECM Summary

B1B2factorcurvesGHz-days
500005000000201.389
50000500000050.347
50000560000070.510
50000594221770.523
50000660000021917.16
50000675000070.554


Lucas-Lehmer results:
No L-L results for M1918351


PRP results:
dateuseridcompidcofactorsres64PRP
2017-10-04T22:11:53Oliver KruseGTX-1
20058278057
14051107599056484017
1425D8996F06DB__no
2017-11-10T00:16:02Chang Chia-Tcheexbpc13
20058278057
14051107599056484017
1425D8996F06DB__no
2020-11-02T18:07:24arnaudSRV-130
20058278057
14051107599056484017
571594571437609699039
D8630AE92355A541no


P-1 factor-bounds graph:
B1 = 1000000, B2 = 71000000 (P-1 stage 2)
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 1000000 (P-1 stage 1)
B1 = 500000 (P-1 stage 1)
100
101
102
103
104
105
106
100
101
102
103
104
105
106
107
108
109
TF factor-bounds graph:
267
230
240
250
260
270
280
290
2100
Last modified: 2022-02-17T11:37:00+00:00