Which one goes after "the"? Possessive or superlative?

Question

I'm trying to construct a sentence, combining possessive and superlative, but confused about the correct placement.

Here's my attempt, tell me which one is correct and why between these two below, thanks in advance!:

The polar form is one of the most world's useful ways of expressing imaginary numbers.

Or

The polar form is one of the world's most useful ways of expressing imaginary numbers.

Answer 1

Only the second version is correct.

It is equivalent to

The polar form is one of the most useful ways in the world of expressing imaginary numbers.

That is, "the world's" can be replaced by "in the world".