\[\boxed{\text{693\ (693).\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[x^{12} - y^{12} = \left( x^{6} - y^{6} \right)\left( x^{6} + y^{6} \right) =\]
\[= (x^{4} - y^{4})(x^{8} + x^{4}y^{4} + y^{8})\]