complex numbers - Why Can my Phone Calculator do $e^{pisqrt{-1}}$ but not $sqrt{-1}$?

When I type in the identity $e^{\pi\sqrt{-1}}$ on my phone calculator (LG phone running Android), I get the correct result of $-1$

However, when I simply type $\sqrt{-1}$, it returns an error.

Why can the calculator do $e^{\pi\sqrt{-1}}$, but not do $\sqrt{-1}$ if $\sqrt{-1}$ is a direct part of $e^{\pi\sqrt{-1}}$?

Answer

$e^{\pi\sqrt{-1}}=\cos \pi + \sqrt{-1}\sin \pi=-1+0=-1$ which is a real number

BUT

$\sqrt{-1}=i$ is a complex number with a zero real part and a non-zero imaginary part.

Computation of complex numbers is possible in any calculator but showing the results containing imaginary numbers is not possible except in certain high-grade calculators.