The number with a prime factorization of 3^4 is
6
12
81
243

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.

You must find the surface of the block therefore 98187 dived by 5628 = 583m squared