\[\boxed{\mathbf{273}.}\]
\[11n^{3} + n = n \cdot \left( 11n^{2} + 1 \right)\]
\[1)\ Пусть\ n\ \vdots 3;\ \ \left( 11n^{3} + n \right)\ \vdots 3.\]
\[Если\ n\ не\ кратно\ 3,\ то\ n =\]
\[= 3n_{1} + 1\ \ или\ \ n = 3n_{1} + 2.\]
\[n = 3n_{1} + 1:\]