find sum of all divisors

gistfile1.txt

    public int divisorSum(int n){
        // n has no divisors other than itself
        if(n == 1){
            return n;
        }

        // Find and sum divisors:
        int half = n/2;
        int sum = n;
        do {
            if(n % half == 0){
                sum += half;
            }
        } while( half-- > 1 );

        return sum;
    }