what should be added to 217139 to make one million?

Let x be added to 217139 to make 1 million.

Also, 1 million = 10000000

So, we have

x + 217139 = 10000000

$$\begin{gathered} \Rightarrow x = 10000000 -217139 \\ \Rightarrow x = 9782861 \end{gathered}$$

Hence, the answer.