Find the square of the following number without actual multiplication $59$.

Consider the following numbers:

$$\begin{gathered} 1. 2222 \\ 2. 11664 \\ 3. 343343 \\ 4. 220347 \end{gathered}$$

Which of the above are not perfect squares?

Arrange the following in the descending order $\left(\sqrt{23}-\sqrt{21}), (\sqrt{19}-\sqrt{17}), (\sqrt{21}-\sqrt{19}\right)$.

Which of the following numbers is not a perfect square?

Find the value of the following, using the diagonal method: $(256{)}^2$

Which of the following numbers is not a perfect square?

The product of two perfect squares is a perfect square.

Find the value of the following, using the diagonal method: $(67{)}^2$