use std::io::*;

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let n: u128 = itr.next().unwrap().parse().unwrap();
    let m: u128 = n * (n + 1) / 2;

    let mut ans = 0u128;
    let mut i = 1u128;
    while i * i <= n {
        if n % i == 0 {
            if m % i == 0 {
                ans += i;
            }
            if i != n / i && m % (n / i) == 0 {
                ans += n / i
            }
        }
        i += 1;
    }
    println!("{}", ans);
}