function is_Natural(n)   
      {  
       if (typeof n !== 'number')   
            return 'Not a number';   
              
     return (n >= 0.0) && (Math.floor(n) === n) && n !== Infinity;  
        }  
console.log(is_Natural(-15));  
console.log(is_Natural(1));<br>console.log(is_Natural(10.22));  
console.log(is_Natural(10/0));