Beginner Trying a complex & tiered if and while statement in Python

New to Python, trying to see why my tiered if and while statements aren't working. Based off of Trinket, my code is blowing up at my second 'if' statement.
Trinket Code

This is what I have:

MIN_VALUE = 2
MAX_VALUE = 100
input_number = input(
    'Enter a number between {} and {}: '.format( MIN_VALUE, MAX_VALUE )
)

if input_number.isdigit():

    userDigitalNumber = int(input_number)

        if ((userDigitalNumber >= MIN_VALUE) and (userDigitalNumber =< MAX_VALUE)):

            while ( range( 1, ( userDigitalNumber + 1 )  )
                totalSum = totalSum + userDigitalNumber
                userDigitalNumber -= userDigitalNumber

else:
    'I''m sorry but your number is not a whole digital number.  Please try again.'
    sys.exit( 1 )

print(
    'The sum of all integers between 1 and {} is {}.'.format( userDigitalNumber, totalSum )
)