Least common multiple Returns the least common multiple of a list of numbers. Use functools.reduce(), math.gcd() and lcm(x, y) = x * y / gcd(x, y) over the given list. from functools import reduce from math import gcd def lcm(numbers): return reduce((lambda x, y: int(x * y / gcd(x, y))), numbers) lcm([12, 7]) # 84 lcm([1, 3, 4, 5]) # 60