The volume of the hemisphere is 19,404 cm³. The radius of the hemisphere is __________.

21 cm

We know that,

Curved surface area of hemisphere = 2πr²

Total Surface area of hemisphere = 2πr² + πr² = 3πr²

Volume of hemisphere = \(\frac{2}{3}\) πr³

\(\frac{2}{3}\) πr³ = 19404

= r = 21 cm

So, the total surface area = 3 × \(\frac{22}{7}\) × (21)² = 4158 cm