365 is not a prime number.

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

For 365, the positive divisors are :

• 1 is a divisor of 365 : $365 / 1 = 365$
• 5 is a divisor of 365 : $365 / 5 = 73$
• 73 is a divisor of 365 : $365 / 73 = 5$
• 365 is a divisor of 365 : $365 / 365 = 1$

Since 365 is divisible by 5 and 73, it has divisors other than 1 and itself.

Therefore, 365 is not a prime number.