That's not good style. The automatic spacing should be the right amount. But if you really want it:
One way to do this would be to put everything in its own math mode:
\documentclass{article}
\begin{document}
$ 1 \land \lnot 2 \lor 3 $ % for comparision
$1$ $\land$ $\lnot$ $2$ $\lor$ $3$
\end{document}

(I put the numbers also in math mode to ensure that always the correct math font is used. By default this doesn't make any difference, though.)
To have the $s added automatically you can use a loop which reads every number, character or macro one by one. Simply group a number with multiple digits together:
\documentclass{article}
\makeatletter
\newcommand\equspacedmath[1]{%
\mbox{% to ensure text mode
\@tfor\L:=#1\do{%
$\L$\space
}%
}%
}
\makeatother
\begin{document}
\equspacedmath{1 \land \lnot 2 \lor 3}
\equspacedmath{1 \land \lnot {23} \lor 4}
$ \equspacedmath{1 \land \lnot 2 \lor 3} $
\[ \equspacedmath{1 \land \lnot {23} \lor 4} \]
\end{document}