$h = 'F23CC481AAE190180000000014000008';;
$n = 0.0; 
( $n *= 2**32 ) += unpack 'N', pack 'H*', $_ for unpack '(A8)*', $h;;

print $n;;
3.21988698417062e+038

printf "%.f\n", $n;;
321988698417062150000000000000000000000