$$\\6^6+6^6+6^6+6^6+6^6+6^6+6^6=6^a\\\\
7*6^6=6^a\\\\
log(7*6^6)=log6^a\\\\
log(7*6^6)=alog6\\\\
\frac{log(7*6^6)}{log6}=a\\\\$$
$${\frac{{log}_{10}\left({\mathtt{7}}{\mathtt{\,\times\,}}{{\mathtt{6}}}^{{\mathtt{6}}}\right)}{{log}_{10}\left({\mathtt{6}}\right)}} = {\mathtt{7.086\: \!033\: \!132\: \!501\: \!691\: \!3}}$$
.$$\\6^6+6^6+6^6+6^6+6^6+6^6+6^6=6^a\\\\
7*6^6=6^a\\\\
log(7*6^6)=log6^a\\\\
log(7*6^6)=alog6\\\\
\frac{log(7*6^6)}{log6}=a\\\\$$
$${\frac{{log}_{10}\left({\mathtt{7}}{\mathtt{\,\times\,}}{{\mathtt{6}}}^{{\mathtt{6}}}\right)}{{log}_{10}\left({\mathtt{6}}\right)}} = {\mathtt{7.086\: \!033\: \!132\: \!501\: \!691\: \!3}}$$