\documentclass[a4paper]{article}
\usepackage{ifthen}
\usepackage[LGR,T1]{fontenc}
\usepackage{booktabs}
\usepackage{longtable,ltcaption,array}
\usepackage[textwidth=14cm]{geometry} % to fit the number table
\setlength{\extrarowheight}{2pt}
\usepackage{parskip}
\pagestyle{empty}

\ifdefined \UnicodeEncodingName
  \usepackage{fontspec}
  \setmainfont{Linux Libertine O} % no GREEK ACROPHONIC ATTIC numbers
  % \setmainfont{Liberation Serif}  % no GREEK ACROPHONIC ATTIC numbers
  % \setmainfont{FreeSerif}
\else
  \usepackage{lmodern}
  % \usepackage{kerkis}   % !! Data loss: \textStigma and \textSampi
                          %    characters missing!
  % \usepackage{gfsdidot} % !! Data loss: \textsampi, \textSampi,
                          %    and \textStigma characters missing!
  % \usepackage{dejavu}   % !! Data loss: \textSampi character missing!
  % Prevent dataloss with re-definitions, e.g:
  % \renewcommand*{\greeknumeralSix}{\textSigma\textTau} % default \textStigma
  % \renewcommand*{\greeknumeralNinety}{\textsampi}      % default \textSampi
\fi

\usepackage[greek,english]{babel}


\begin{document}
\section*{Test Greek (Milesian) numerals}
\author{Günter Milde}
\date{2023/01/06}

Babel-greek defines the functions \verb|\greeknumeral| and
\verb|\Greeknumeral| that work similar to the TeX primitive
\verb|\romannumeral|. For details and configuration options, see
\texttt{babel-greek.pdf}.

% Compare also with the "ready-made" counter styles for CSS
% https://www.w3.org/TR/predefined-counter-styles/#greek-styles
%
% CSS counters greek-lower-modern and greek-upper-modern
% use Sigma+Tau instead of Stigma for 6.
%
% CSS counters greek-lower-ancient and greek-upper-ancient use Stigma

Examples:
\newcommand*{\greeknumeralsample}[1]{\mbox{#1 = \greeknumeral{#1}}}
\newcommand*{\Greeknumeralsample}[1]{\mbox{#1 = \Greeknumeral{#1}}}

\greeknumeralsample{16}\quad
\greeknumeralsample{32}\quad
\greeknumeralsample{64}\quad
\greeknumeralsample{678}\quad
\greeknumeralsample{2022}\quad
\greeknumeralsample{123456}

\Greeknumeralsample{16}\quad
\Greeknumeralsample{32}\quad
\Greeknumeralsample{64}\quad
\Greeknumeralsample{678}\quad
\Greeknumeralsample{2022}\quad
\Greeknumeralsample{123456}

Hexadecimal input works, too: \greeknumeralsample{"10}

Largest supported number: \greeknumeralsample{999999}

Values outside the supported range are printed as arabic decimal numbers
(a warning is issued):
\greeknumeralsample{-1}\quad
\greeknumeralsample{0}\quad
\greeknumeralsample{"1000000}

All Ionic number symbols.
The Greek font encoding is \greekfontencoding.

\begin{tabular}{rrrrrrrrr}
\toprule
1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\
\greeknumeral{1} & \greeknumeral{2} & \greeknumeral{3} & \greeknumeral{4} &
\greeknumeral{5} & \greeknumeral{6} & \greeknumeral{7} & \greeknumeral{8} & \greeknumeral{9} \\[0.3em]

10 & 20 & 30 & 40 & 50 & 60 & 70 & 80 & 90 \\
\greeknumeral{10} & \greeknumeral{20} & \greeknumeral{30} & \greeknumeral{40} &
\greeknumeral{50} & \greeknumeral{60} & \greeknumeral{70} & \greeknumeral{80} & \greeknumeral{90} \\[0.3em]

100 & 200 & 300 & 400 & 500 & 600 & 700 & 800 & 900 \\
\greeknumeral{100} & \greeknumeral{200} & \greeknumeral{300} & \greeknumeral{400} &
\greeknumeral{500} & \greeknumeral{600} & \greeknumeral{700} & \greeknumeral{800} & \greeknumeral{900} \\[0.3em]

1000 & 2000 & 3000 & 4000 & 5000 & 6000 & 7000 & 8000 & 9000 \\
\greeknumeral{1000}& \greeknumeral{2000}& \greeknumeral{3000}& \greeknumeral{4000}&
\greeknumeral{5000}& \greeknumeral{6000}& \greeknumeral{7000}& \greeknumeral{8000}& \greeknumeral{9000} \\[0.3em]

10000 & 20000 & 30000 & 40000 & 50000 & 60000 & 70000 & 80000 & 90000 \\
\greeknumeral{10000}&\greeknumeral{20000}&\greeknumeral{30000}&\greeknumeral{40000}&
\greeknumeral{50000}&\greeknumeral{60000}&\greeknumeral{70000}&\greeknumeral{80000}&\greeknumeral{90000} \\[0.3em]

100000 & 200000 & 300000 & 400000 & 500000 & 600000 & 700000 & 800000 & 900000 \\
\greeknumeral{100000}&\greeknumeral{200000}&\greeknumeral{300000}&\greeknumeral{400000}&
\greeknumeral{500000}&\greeknumeral{600000}&\greeknumeral{700000}&\greeknumeral{800000}&\greeknumeral{900000} \\[0.3em]

\bottomrule
\end{tabular}

\begin{tabular}{rrrrrrrrr}
\toprule
1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\
\Greeknumeral{1} & \Greeknumeral{2} & \Greeknumeral{3} & \Greeknumeral{4} &
\Greeknumeral{5} & \Greeknumeral{6} & \Greeknumeral{7} & \Greeknumeral{8} & \Greeknumeral{9} \\[0.3em]

10 & 20 & 30 & 40 & 50 & 60 & 70 & 80 & 90 \\
\Greeknumeral{10} & \Greeknumeral{20} & \Greeknumeral{30} & \Greeknumeral{40} &
\Greeknumeral{50} & \Greeknumeral{60} & \Greeknumeral{70} & \Greeknumeral{80} & \Greeknumeral{90} \\[0.3em]

100 & 200 & 300 & 400 & 500 & 600 & 700 & 800 & 900 \\
\Greeknumeral{100} & \Greeknumeral{200} & \Greeknumeral{300} & \Greeknumeral{400} &
\Greeknumeral{500} & \Greeknumeral{600} & \Greeknumeral{700} & \Greeknumeral{800} & \Greeknumeral{900} \\[0.3em]

1000 & 2000 & 3000 & 4000 & 5000 & 6000 & 7000 & 8000 & 9000 \\
\Greeknumeral{1000}& \Greeknumeral{2000}& \Greeknumeral{3000}& \Greeknumeral{4000}&
\Greeknumeral{5000}& \Greeknumeral{6000}& \Greeknumeral{7000}& \Greeknumeral{8000}& \Greeknumeral{9000} \\[0.3em]

10000 & 20000 & 30000 & 40000 & 50000 & 60000 & 70000 & 80000 & 90000 \\
\Greeknumeral{10000}&\Greeknumeral{20000}&\Greeknumeral{30000}&\Greeknumeral{40000}&
\Greeknumeral{50000}&\Greeknumeral{60000}&\Greeknumeral{70000}&\Greeknumeral{80000}&\Greeknumeral{90000} \\[0.3em]

100000 & 200000 & 300000 & 400000 & 500000 & 600000 & 700000 & 800000 & 900000 \\
\Greeknumeral{100000}&\Greeknumeral{200000}&\Greeknumeral{300000}&\Greeknumeral{400000}&
\Greeknumeral{500000}&\Greeknumeral{600000}&\Greeknumeral{700000}&\Greeknumeral{800000}&\Greeknumeral{900000} \\

\bottomrule
\end{tabular}

\end{document}