A natural number is divisible by 2 if and only if the last digit is even (divisible by 2).
A natural number is divisible by 2 if and only if the last digit of the number is 0, 2, 4, 6 or 8.
716 is divisible by 2 since the last digit (6) is even (divisible by 2).
717 is NOT divisible by 2 since the last digit (7) is odd (NOT divisible by 2).
716 123 456 789 098 765 432 104 is divisible by 2 since the last digit (4) is even (divisible by 2).
717 123 456 789 098 765 432 109 is NOT divisible by 2 since the last digit (9) is odd (NOT divisible by 2).