The divisor is an element of a division operation.
<math> \frac{\displaystyle dividend}{\displaystyle divisor} = quotient </math>
If d is a divisor of N then N/d is also a divisor of N.
If d is a divisor of N, d is trivial if its value is 1 or N.
Euclid's algorithm for greatest common divisor. This algorithm that dates back some 2300 years is attributed to Euclid, and is very fast.
def gcd(x,y): return x if y == 0 else gcd(y, x % y)