The current software only allows exponents of 2, 3.
Most fonts only have 1, 2, and 3, because those were included in the
basic set of characters many moons ago. A few fonts, including Lucida
Sans, Arial Unicode, Cambria, Calibri, and Cambria Math, have the rest
of them. In Insert Symbol, set the upper-right dropdown to
"Superscripts and Subscripts," and if you don't get a full set, select
one of the above fonts from the fonts dropdown at the upper left.
If you don't want to do it that way, then use the Superscript format:
select the number (etc.) to be raised and press Ctrl-Shift-+. (For
subscripts, it's Ctrl-=.)
Or, you could make a Character Style with Superscript selected in the
Font formatting panel.
