A prime number is a number that is only evenly divisble by itself and 1.

For example, the number 5 is prime because it can only be evenlly divided by 1

and 5. The number 6, however, is not prime because it can be divided evenly

by 2 and 3.

Write a Boolean function named is_prime which takes an integer as an argument

and returns true if the argument is a prime number, or false otherwise. Use

the function in a program that prompts the user to enter a number and then

prints whether the number is prime.

Let's be honest, there are plenty of solutions on the internet. Here's one where I added a program to use it. Note that this one is optimized to not consider even numbers, and to only iterate to the squareroot of the number you're testing.

def is_prime (n):

if n = = 2 or n = = 3: return True

if n % 2 = = 0 or n < 2: return False

for i in range (3, int (n**0.5) + 1, 2):

if n % i = = 0:

return False

return True

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

print ("{} is {}a prime.". format (x, "" if is_prime (x) else "not "))