How to insert page number in Beamer navigation symbols?

You can use something like

\addtobeamertemplate{navigation symbols}{}{%
    \usebeamerfont{footline}%
    \usebeamercolor[fg]{footline}%
    \hspace{1em}%
    \insertframenumber/\inserttotalframenumber
}

and use spaces, font and boxes to adjust the alignment of the numbers with the navigation symbols.

You can change the font/color just by altering the font/color for footline as in

\setbeamercolor{footline}{fg=blue}
\setbeamerfont{footline}{series=\bfseries}

You can add the following code before \begin{document}:

\expandafter\def\expandafter\insertshorttitle\expandafter{%
  \insertshorttitle\hfill%
  \insertframenumber\,/\,\inserttotalframenumber}

Before \begin{document} you need to include:

\setbeamertemplate{sidebar right}{}
\setbeamertemplate{footline}{%
\hfill\usebeamertemplate***{navigation symbols}
\hspace{1cm}\insertframenumber{}/\inserttotalframenumber}

This should work to put the frame number beside the navigation bar, not sure how to put it inside of the navigation bar.