def check_abbrv(num):
    """
    Checks to see if the number is abbreviated. Returns True if the number is abbreviated and False if it is not.
    """
    try:
        int(num)
        return False
    except ValueError:
        letter = num[-1].upper()
        abbrv = ("T", "B", "M", "K")
        if letter in abbrv:
            return True
        else:
            return "invalid"