15 to the 27th power

you can write 15^27 like this:

15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*15*

Or-------------------------------------------------------------------------------

use a calculator.

$${{\mathtt{15}}}^{{\mathtt{27}}} = {\mathtt{56\,815\,128\,661\,595\,284\,938\,812\,255\,859\,375}}$$

so, $${\mathtt{56\,815\,128\,661\,595\,284\,938\,812\,255\,859\,375}}$$  is our final answer.