Since $\displaystyle{66150}={9}\cdot{7350}={9}\cdot{25}\cdot{294}={9}\cdot{25}\cdot{49}\cdot{6}\usepackage{cmbright}\Huge\$ , this means that $\displaystyle\sqrt{{66150}}=\sqrt{{{{3}}^{{2}}\cdot{{5}}^{{2}}\cdot{{7}}^{{2}}\cdot{6}}}={3}\cdot{5}\cdot{7}\cdot\sqrt{{6}}={105}\sqrt{{6}}\usepackage{cmbright}\Huge\$ .