for n=1:5000000

   digs=char(string(n));

   s1=sod(n);

   s2=flip(char(string(s1)));

   if s1*str2double(s2)==n

       disp(n)

   end

end

function sd = sod(n) 

    s=0;

    dgts=num2str(n) ;

    l=length(dgts) ;

    for i=1:l

        s=s+str2double(dgts(i));

    end

    sd=s;

end

finds only

     1
    81
  1458
  1729

  

and in fact the checking to 5 million is overkill:

Maximum SODs are proportional to log(n), and the product of two SODs to the square of log(n). At five digit n, the maximum SOD is 9*5=45, whose square is 2025, and thus already too small to match a 5-digit number. This is all the more so for higher numbers of digits; for example (9*6)^2 = 2916, too small to match a 6-digit number.