(6^12 x 35^28 x 15^16)/ 14^12 x 21^11
take the numerator first
6^12 = 2^12 * 3^12
35^28 = 7^28 * 5^28
15^16 = 3^16 * 5^16
denominator
14^12 = 2^12 * 7^12
21^11 = 3^11 * 7 *11
5^28 = 1^28 * 5^28
we can cancel 2^12, 7^23 , 3^11 and 5^28
we are left with
3* 5^16 * 7^5 * 3^16
1+16+5+16 = 38 ( prime factor )