На Python:

def is_prime(number):

   if number <= 1:

       return False

   for i in range(2, number):

       if number % i == 0:

           return False

       if i * i > number:

           break

   return True

number = int(input("Enter a number: "))

if is_prime(number):

   print(number, "is a prime number")

else:

   print(number, "is not a prime number")