Numbers divisible by the sum and product of their digits

05AB1E, 13 12 bytes

Thanks to Emigna for saving a byte!

µNNSONSP‚ÖP½

Explanation:

µ          ½   # Get the nth number for which the following holds:
  NSO          #   The sum of digits of the current number
     NSP       #   And the products of digits of the current number
 N      ‚ÖP    #   Divides the current number
               # If the nth number has been reached, quit and implicitly print N

Uses the CP-1252 encoding. Try it online!

Pyke, 14 bytes (non-competitive) (1-indexed)

~1IY'sB]im%X)@

Try it here!

My god what a lot of new features.

~1             -   infinite list of natural numbers
  IY'sB]im%X)  -  filter(^, V) - remove if any truthiness
   Y           -      digits(i)
    'sB]       -     [sum(^), product(^)]
        im%    -    map(^, %i)
           X   -   splat(^)
             @ - ^[input]

Of which are non-competitive

• a bugfix in I where it would only check if the first item on the stack was truthy
• digits - return a list of digits in the number
• @ used to get the nth item of an infinite list

Of which were being used for the first time:

• all of the above
• infinite lists

Remove the last 2 bytes to get all of these numbers.

C#, 118 bytes

n=>{int x=0,c=0;for(;;){int s=0,p=1,i=++x;while(i>0){s+=i%10;p*=i%10;i/=10;}if((c+=p>0&&x%s+x%p<1?1:0)==n)return x;}};

Full program with ungolfed function and test cases:

using System;

public class Program
{
    public static void Main()
    {
        // x - output number
        // c - counter
        // s - sum
        // p - product
        // i - iterator
        Func<int,int>f= n=>
        {
            int x=0, c=0;
            for ( ; ; )
            {
                int s=0, p=1, i=++x;
                while (i > 0)
                {
                    s += i%10;
                    p *= i%10;
                    i /= 10;
                }
                if ( (c += p> 0&& x%s+x%p<1 ? 1 : 0) == n)
                    return x;
            }
        };
        
        // tests:
        Console.WriteLine(f(1));  //1
        Console.WriteLine(f(5));  //5
        Console.WriteLine(f(10)); //12
        Console.WriteLine(f(20)); //312
        Console.WriteLine(f(42)); //6912
        Console.WriteLine(f(50)); //11313
    }
}