Kanel-Belov A.Ya.

Does there exist a number whose square, in its decimal representation, contains the sequence of digits "2018"?
Indeed,

$$
\left(5 \cdot 10^{6}+2018\right)^{2}=25 \cdot 10^{12}+2018 \cdot 10^{7}+4072324
$$

so the square of this number contains the digit sequence "2018".

## Answer

Yes, for example, 5002018.