78 is a composite number. A composite number is defined as any positive integer greater than 1 that is not prime, meaning it has more than two distinct positive divisors.
In the case of 78, its divisors include 1, 2, 3, 6, 13, 26, 39, and 78. Since 78 can be divided evenly by numbers other than 1 and itself, it fits the definition of a composite number.
Furthermore, we can find its prime factorization which is 2 × 3 × 13. This factorization confirms that 78 is composite because it can be expressed as the product of smaller integers. Therefore, 78 is not a prime number.