From Why start at x, y, z

Superscripts are most commonly[1] used to denote powers, eg \(4^3=64\).

Superscripts are also commonly used to mark footnotes. If there is a footnote about a number, this can lead to an ambiguity, for example: there are 47[2] pages on this wiki. (Wiki styling puts square brackets around this reference, making this less ambiguous, but this is not always the case elsewhere.)

  1. But there are some other common uses of superscripts, see eg powers of trigonometric functions.
  2. This number is a guess, I didn't count them.