Is $N$ considered a proper divisor of $N$

Question

I just started Project Euler and I have run into an issue. There are numerous problems that ask about the proper divisors, sum of proper divisors, etc. of a number $N$. Now, before I proceed, I would like to make sure my vocabulary is correct. Is $N$ be considered a proper divisor of $N$? I have always said no, but since it does divide it, is the standard to include $N$ in a list of proper divisors?

Answer 1

No.

Indeed, the fact that $N$ is a divisor and not a proper divisor is the only difference between the words "divisor" and "proper divisor".