Introduction
 Divisibility is a property of a pair of numbers.
 Given two numbers: d and n, we can say d divides n if there is a third number k in which dk = n

This property also goes by other names:
 n is a multiple of d
 d is a factor or divisor of n
 n is the dividend

if d divides n then we write it as:
LaTeX:d \mid n

if d does not divide n then we write it as:
LaTeX:d \nmid n
Example
 Given the two numbers: 7 and 42, we can say that 7 divides 42 because there is third number: 6 which forms the equality 6 * 7 = 42

This can be written as:
Code
def is_divisible(divisor, dividend): return dividend % divisor == 0 print(is_divisible(7, 42)) # prints True print(is_divisible(4, 42)) # prints False