Divisibility is a mathematical relationship between two integers. An integer is divisible by another integer if there is no remainder in the division. The number 11 has only two divisors: 1 and the number 11 itself, whereas the number 12 has many divisors: 1, 2, 3, 4, 6 and 12.
In elementary number theory, the concept of divisibility is limited to natural numbers.
The number of its divisors can be determined with the function `length()`

.