strong_number.js

<script>
var a=prompt("Enter a value");
z=a;
e = d = 0;
while(z > 0)
{
e = z % 10;
d = d + fact(e);
z = parseInt(z/10); 
}
if(d==a)
{
alert("Given number is a strong number");
}
else {
alert("Give number is not a strong number");
}

function fact(x) {
       if(x == 0) {
           return 1;
       }
       if(x < 0 ) 
       {
           return undefined;
       }
       for(i = x; --i; ) 
       {
           x *= i;
       }
       return x;
}
 
</script>