How to check if a number is prime?

number = int(input("Write a number: ")
  
# If given number is greater than 1
if number > 1:
  
    # Iterate from 2 to n / 2
    for e in range(2, int(number/2)+1):
  
        # If num is divisible by any number between
        # 2 and n / 2, it is not prime
        if (number % e) == 0:
            print(number, "is not a prime number")
            break
    else:
        print(number, "is a prime number!")

# Output:
11 is a prime number!

Additional information

Prime number - It is a positive natural number that has only two positive natural number divisors, the number one and the number itself.

• The number 1 is not a prime number by definition, it has only one divisor.

• The number 0 is not a prime number, it is not a positive number and has infinite number of divisors.

Example: - The number 13 has only two divisors of 1,13:

13/1 = 13
13/13 = 1

Example: - The number 15 is not a prime number, thi has more than 2 divisors:

15/1 = 15
15/3 = 5
15/5 = 3
15/15 = 1

List of prime numbers up to 100:

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, ...

References

Prime numbers

Program to check if a number is prime

Program to check if a number is prime using input