if [ $# -eq 1 ]
        then
             if [ $1 -gt 0 ]
             then
                 num=$1
                 sumi=0
                 while [ $num -ne 0 ]
                 do
                 lnum=`expr $num %  10`
                 sumi=`expr $sumi * 10 + $lnum`
                 num=`expr $num \/ 10`
                 done
                 echo "Reverse of digits is  $sumi of $1"else
                 echo " Number is less than 0"
               fi
    else
            echo "Insert only one parameter "
    fi     

--------------------------------------------------------------------------------         

output:

       $ sh1 23456
       Reverse of digits is 65432 of   23456