Number Theory, GCD, and Modular Arithmetic - Lecture 19 (Discrete Math)

The greatest common divisor of integers a and b is defined as a common divisor d such that:

1. A.For any other common divisor e, d is greater than or equal to e.
2. B.For any other common divisor e, d is strictly greater than e.
3. C.d is the smallest positive integer dividing both a and b.
4. D.d is equal to the product of a and b divided by their sum.