use Math::BigFloat;
my($out,$diver,$grade) = map{ 
    Math::BigFloat->new( $_ ) 
} split(/,/, ' 2.84894533078051,5,0.002', 3);

print $out ** ( 1/$grade ) * $diver;
109907610023675317191879876436497649438076948727516195849531
529984640080900905500623346430661197750153976478077957100021
178235709357073884306056471657477469213296476869314035526387
8485678475840878789876340877189092206814894928600.3227150712
343412750871362367932483896648862164560115552012310931635017
...
<lots more snipped>
...
198626328593786831872991187091247473250005
perl>