Is 79 a prime number?

To determine if 79 is a prime number, we need to check if it is divisible by any positive integer other than 1 and itself.

A prime number is a number greater than 1 that has no divisors other than 1 and itself.
We check if 79 is divisible by any integer between 2 and the square root of 79 (approximately 8.88). We round this down to 8.
We test the divisibility of 79 by the prime numbers less than or equal to 8: 2, 3, 5, and 7.
79 is not divisible by 2 because it is odd.
79 is not divisible by 3 because the sum of the digits of 79 (7 + 9 = 16) is not divisible by 3.
79 is not divisible by 5 because it does not end in 0 or 5.
79 is not divisible by 7 because 79 ÷ 7 ≈ 11.29, which is not an integer.
Since 79 is not divisible by any of these numbers, it is a prime number.

Thus, 79 is a prime number.