import java.util.Scanner;
public class 完数 {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n =sc.nextInt();
int total = 0;
for(int i = 1;i<n/2+1;i++) {
if(n%i == 0)
total = total+i;
}
if(total == n) {
System.out.println("yes");
}
else
System.out.println("no");
}
}