# Extract multiplier from siunitx prefix

Is there a way to extract the multiplication factor that each siunitx prefix represents. Basically, can I automate ExplainPrefix to correctly produce the correct output. Current output uses x as the exponent:

## MWE:

\documentclass{article}

\usepackage{siunitx}
\usepackage{expl3}

%% http://tex.stackexchange.com/questions/100542/how-to-extract-the-name-of-a-macro
\ExplSyntaxOn
\newcommand{\CsToStr}[1]{\cs_to_str:N #1}
\ExplSyntaxOff

\newcommand{\ExplainPrefix}[1]{%
\par
The prefix \CsToStr{#1} (symbol: \si{#1}) representes multiplication by $10^x$.
}%

\DeclareSIPrefix\wacky{X}{41}

\begin{document}

\ExplainPrefix{\kilo}
\ExplainPrefix{\micro}
\ExplainPrefix{\wacky}

\end{document}

-

\si[prefixes-as-symbols = false]{#1}

The data for this conversion is stored in the internal property list \l__siunitx_prefix_forward_prop, which may of course change in the future but is there if you want to do something more complex.