Express the given number as a power of a base $\mathrm{<mn>3</mn>}$:

${{\mathrm{<mn>3</mn>}}^{\mathrm{<mn>3</mn>}}·\left({\mathrm{<mn>3</mn>}}^{\mathrm{<mn>7</mn>}}\right)}^{\mathrm{<mn>3</mn>}}=$