+14538 $${{\mathtt{9}}}^{{\mathtt{4}}} = {\mathtt{6\,561}}$$
$${{\mathtt{9}}}^{{\mathtt{4}}} = {\mathtt{9}}{\mathtt{\,\times\,}}{\mathtt{9}}{\mathtt{\,\times\,}}{\mathtt{9}}{\mathtt{\,\times\,}}{\mathtt{9}} = {\mathtt{6\,561}}$$
$${{\mathtt{9}}}^{{\mathtt{4}}} = {\left({{\mathtt{3}}}^{{\mathtt{2}}}\right)}^{{\mathtt{4}}} = {{\mathtt{3}}}^{{\mathtt{8}}} = {\mathtt{6\,561}}$$
.+14538 $${{\mathtt{9}}}^{{\mathtt{4}}} = {\mathtt{6\,561}}$$
$${{\mathtt{9}}}^{{\mathtt{4}}} = {\mathtt{9}}{\mathtt{\,\times\,}}{\mathtt{9}}{\mathtt{\,\times\,}}{\mathtt{9}}{\mathtt{\,\times\,}}{\mathtt{9}} = {\mathtt{6\,561}}$$
$${{\mathtt{9}}}^{{\mathtt{4}}} = {\left({{\mathtt{3}}}^{{\mathtt{2}}}\right)}^{{\mathtt{4}}} = {{\mathtt{3}}}^{{\mathtt{8}}} = {\mathtt{6\,561}}$$
