Given a positive integer $x$ let $n_x = lfloor log_{10} x rfloor$ and let $x_0, x_1, dots, x_{n_x} in {0, 1, 2, 3, 4, 5, 6, 7 ,8 ,9}$ such that $x = sum_{i=0}^{n_x} 10^i x_i$.

Define the multiset $S(x) = {x_0, x_1, dots, x_{n_x} }$.

The problem is asking for:

$$

min x quadmbox{ s.t.}\

S(x)=S(ix) quad forall i in {2,3,4,5,6}; \

x in mathbb{Z}; \

x > 0.

$$