👉 Regnum in classical Greek mathematics refers to the number of divisors a given number has, including 1 and itself. For example, the number 6 has 2 divisors (1 and 6), but it is also divisible by 3 since 3 is a divisor of 6. In modern mathematical terminology, regnum can be defined as the total number of positive divisors of a given integer n, including both 1 and n itself. For example: - The number