888 is not a prime number.

A prime number has only two positive divisors: 1 and itself.

For 888, the positive divisors are :

• 1 is a divisor of 888 : $888 / 1 = 888$
• 2 is a divisor of 888 : $888 / 2 = 444$
• 3 is a divisor of 888 : $888 / 3 = 296$
• 4 is a divisor of 888 : $888 / 4 = 222$
• 6 is a divisor of 888 : $888 / 6 = 148$
• 8 is a divisor of 888 : $888 / 8 = 111$
• 12 is a divisor of 888 : $888 / 12 = 74$
• 24 is a divisor of 888 : $888 / 24 = 37$
• 37 is a divisor of 888 : $888 / 37 = 24$
• 74 is a divisor of 888 : $888 / 74 = 12$
• 111 is a divisor of 888 : $888 / 111 = 8$
• 148 is a divisor of 888 : $888 / 148 = 6$
• 222 is a divisor of 888 : $888 / 222 = 4$
• 296 is a divisor of 888 : $888 / 296 = 3$
• 444 is a divisor of 888 : $888 / 444 = 2$
• 888 is a divisor of 888 : $888 / 888 = 1$

Since 888 is divisible by 2, 3, 4, 6, 8, 12, 24, 37, 74, 111, 148, 222, 296 and 444, it has divisors other than 1 and itself.

Therefore, 888 is not a prime number.