Chapter 4 - Number Representation and Calculation - 4.1 Our Hindu-Arabic System and Early Positional Systems - Exercise Set 4.1 - Page 218: 59

$29,520,244$

Using the table and that the place values are $1,20,18\cdot20=360,18\cdot20^2=7200,18\cdot20^3=144000, 18\cdot20^4=2,880,000$: The numerical value as a Hindu- Arabic numeral is: $10\cdot2,880,000+5\cdot144000+0\cdot7200+0\cdot360+11\cdot20+4\cdot1=28,800,000+720000+0+0+220+4=29,520,244$