Diameter of sphere = 21 cm

Hence, radius of the sphere =

Volume of sphere = π × r³ =

Volume of cube = a³ = 1³

Let the number of cubes formed be n

Volume of sphere = n(volume of cube)

= n × 1

4 × 22 × = n × 1

11 × 21 × 21 = n × 1

4851 = n

So,

Hence, the number of cubes is 4851