In alkaline medium, ${\mathrm{KMnO}}_4$ reacts as follows 

$2{\mathrm{KMnO}}_4 + 2\mathrm{KOH} \to 2{\mathrm{K}}_2{\mathrm{MnO}}_{4 } + {\mathrm{H}}_2\mathrm{O} + \mathrm{O}$

Therefore, the equivalent mass of  ${\mathrm{KMnO}}_4$ will be