63 is a composite number.
A prime number is defined as a number that has exactly two distinct positive divisors: 1 and itself. In contrast, a composite number has more than two positive divisors. For the number 63, it can be factored into 3 and 21, as well as 7 and 9, which means it can be divided evenly by numbers other than 1 and 63. Specifically, the divisors of 63 are 1, 3, 7, 9, 21, and 63.
Since 63 can be divided by multiple numbers without leaving a remainder, it confirms that 63 is a composite number.