is 2 1872547 - 1
has 563693 decimal digits
takes 0.102 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
Actual26715.868268.6567%500000150000000.10155.0826%15.969770.2498%1.5931%
PrimeNet2570.010363.1579%90001600000.00143.0299%0.011664.2742%1.1163%
GPU722610.164065.5738%100001500000.00141.6901%0.165466.1556%0.5818%
Difference+6+15.7041+3.0829%+490000+14850000+0.1001+3.3925%+15.8042+4.0942%+4.0942%

Known prime factors (3 factors, 195.6 bits, 0.01044498% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
187254720417200116586011650.859545171900
22 × 52 × 7 × 13 × 139 × 431
-1394310.00011.219e-52.225e-5
1872547721923061691653861192065.96819276500448097
19 × 1014552655163
2018-04-151910145526551635.46564,348.18,121.1
18725475118127481359061611698172478.760136662190090797764
22 × 31 × 211 × 283 × 13681 × 1349087
2015-08-1713681134908758,9020.00680.0108

4 Composite Factors:
exponentprime factorscomposite factordigitsbits*
187254714739647619336964504302241977235951936116.827
1872547104497833009106294461366247176058964601740129.619
18725473694894261470926833349381007024513753357022344144.728
187254775439395546077186658653072398760169783811026397579
335438023
59195.587
P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2015-08-17T12:52:00alpertronManual testing50000015000000122478.7600.1010.2030.2035.083%


Trial Factoring results:
No TF results for M1872547


ECM factoring results:

Old Calculation Method

Total ECM effort:19.258 GHz-days
Estimated T-Level:24.482
DigitsB1CurvesCompleteFacMiss
2011000251 / 1002.5108.025%
2550000251 / 2800.89640.737%

New Calculation Method

Total ECM effort:19.258 GHz-days
Estimated T-Level:24.482
DigitsB1CompleteFacMiss
20110008.5680.019%
25500000.77646.015%
302500000.04895.312%
3510000000.00299.779%


ECM Summary

B1B2factorcurvesGHz-days
500005000000382.631
50000500000010.069
50000660000021216.56


Lucas-Lehmer results:
No L-L results for M1872547


PRP results:
dateuseridcompidcofactorsres64PRP
2017-09-30T15:24:53alpertronManual testing
2041720011658601
511812748135906161169817
8F3EFB95D22A92__no
2017-10-20T01:48:42Oliver KruseThreadripper
2041720011658601
511812748135906161169817
8F3EFB95D22A92__no
2018-04-17T16:33:00Oliver KruseGTX-2
2041720011658601
72192306169165386119
511812748135906161169817
368DCFC82BFFC6__no
2018-04-19T00:57:23BattlemaxxWork-2
2041720011658601
72192306169165386119
511812748135906161169817
368DCFC82BFFC6__no


P-1 factor-bounds graph:
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
100
101
102
103
104
105
106
100
101
102
103
104
105
106
107
108
109
1010
1011
1012
1013
TF factor-bounds graph:
267
250
260
270
280
290
2100
Last modified: 2021-09-10T07:34:27+00:00