In the analogy 36 : 54 :: 47 : ?, what number belongs in place of the question mark?

The two digits are multiplied together and the product is added to the number itself. For 36 that is $3\times 6=18$ and 18 + 36 = 54; for 47 it is $4\times 7=28$ and 28 + 47 = 75. The trap 28 stops at the product and forgets to add, but the product for 36 is 18 and not 54. 58 adds the digit sum instead, and 36 + 9 = 45, while 94 simply doubles 47, where doubling 36 gives 72.