A number never have a odd divisor which can be represent as the power of two. A famous way to find out the number can be represent as the power of two or not is:]

n & (n — 1) by this operation we will get a number which is an even number also the number can be represent by the power of two.So if by doing this operation we get any number which is represent by the power of two.That means 'n' has no odd divisor.watch the problem 1475A

A number can be represent as the sum of k odd number when the n%2 == k%2

and obviously k*K should less then n.

The statement of 1327A is also saying that.