python

Prime Number

# Prime Number
n=int(input('Enter a number: '))
div = 2
while div < n: 
    if n % div == 0:   
        print(' Not a Prime Number')
        break
    div+=1
else:
    print('Prime Number')

Output:
Enter a number: 5
Prime Number

Enter a number: 4
Not a Prime Number

To check factorial

# check factorial
n=int(input('Enter a number: '))
total = 0
factor = 1
while factor < n:
    if n % factor == 0:
        total = total + factor
    factor += 1
    if total == n:
        print("Perfect Number")
        break
else:
    print("Not a Perfect Number")

Output:
Enter a number: 8
Not a Perfect Number

Enter a number: 4
Perfect Number

20) A number is a perfect number if the sum of its factors other than the given number gives the same number. For example, 6 is a perfect number, since adding the factors of 6 (other than 6), namely 1, 2 and 3 gives the given number 6. i.e.,1+2+3 = 6 is the given number.
Check whether 28, 54 and 496 are perfect numbers or not.

n=int(input('Enter a number: '))
total = 0
factor = 1
while factor < n:
    if n % factor == 0:
        total = total + factor
    factor += 1
    if total == n:
        print("Perfect Number")
        break
else:
    print("Not a Perfect Number")

Output:
Enter a number: 6
Perfect Number

Enter a number: 28
Perfect Number

Enter a number: 54
Not a Perfect Number

Enter a number: 496
Perfect Number

Express 42 and 100 as the sum of two consecutive primes.
42 = 19 + 23
19 and 23 are consecutive primes

100 = 47 + 53
47 and 53 are consecutive primes

Divisible by 2
Last number will be 2,4,6,8,0

# Divisible by 2
n = int(input('Enter a number: '))
last_digit = n%10 
if last_digit in (0,2,4,6,8):
    print('Divisible by 2')
else:
    print('Not Divisible by 2')

Output:
Enter a number: 23
Not Divisible by 2

Divisible by 3
The sum of number divisible by 3

n = int(input('Enter a number: '))
if n % 3 == 0:
    print('Divisible by 3')
else:
    print('Not Divisible by 3')

Output:
Enter a number: 5
Not Divisible by 3

no = 15
ones_place = no % 10  #5
tens_place = no // 10 #1
sum = ones_place + tens_place
if sum%3 ==0:
    print("Divisible by 3")

Output:Divisible by 3

Divisible by 4
last two digit divided by 4

# Divisible by 4
n = int(input("Enter a number: "))
last_two = n % 100
if last_two % 4 == 0:
    print("Divisible by 4")
else:
    print("Not Divisible by 4")

Output:
Enter a number: 432
Divisible by 4

Divisible by 5
last digit will be 0 or 5

# Divisible by 5
n = int(input("Enter a number: "))
last_digit = n % 10
if last_digit == 0 or last_digit == 5:
    print("Divisible by 5")
else:
    print("Not Divisible by 5")

Output:
Enter a number: 999
Not Divisible by 5

Divisible by 6
Given number will be divided by 2 and 3

n = int(input("Enter a number: "))
if n % 2 == 0 and n % 3 == 0:
    print("Divisible by 6")
else:
    print("Not Divisible by 6")

Output:
Enter a number: 36
Divisible by 6

Divisible by 8
last three digit divided by 8

# Divisible by 8
n = int(input("Enter a number: "))
last_three = n % 1000
if last_three % 8 == 0:
    print("Divisible by 8")
else:
    print("Not Divisible by 8")

Output:
Enter a number: 6789
Not Divisible by 8

Divisible by 9
sum of digit divided by 9

n = int(input("Enter a number: "))
sum_digits = 0
while n > 0:
    digit = n % 10
    sum_digits = sum_digits + digit
    n = n // 10
if sum_digits % 9 == 0:
    print("Divisible by 9")
else:
    print("Not Divisible by 9")

Output:
Enter a number: 81
Divisible by 9

Divisible by 10
last digit will be 0

# Divisible by 10
n = int(input("Enter a number: "))
last_digit = n % 10
if last_digit == 0:
    print("Divisible by 10")
else:
    print("Not Divisible by 10")

Output:
Enter a number: 65
Not Divisible by 10

Divisible by 11
sum of even-odd=0

n = int(input("Enter a number: "))
even_sum = 0
odd_sum = 0
position = 1
while n > 0:
    digit = n % 10
    if position % 2 == 0:
        even_sum = even_sum + digit
    else:
        odd_sum = odd_sum + digit
    n = n // 10
    position += 1
difference = even_sum - odd_sum

if difference == 0 or difference % 11 == 0:
    print("Divisible by 11")
else:
    print("Not Divisible by 11")

Output:
Enter a number: 1224
Not Divisible by 11