def is_number(word):
    """ Function that returns 'NUM' if a shipo word is a number or False if not

        :param word: a word to be evaluated
        :type word: str
        :returns: 'NUM' if a shipo word is a number or False if not
        :rtype: str

        :Example:

        >>> import chana.ner
        >>> chana.ner.is_number('kimisha')
        'NUM'
        
    """
    numbers = ['westiora', 'rabé', 'kimisha', 'chosko', 'pichika', 'sokota',
        'kanchis', 'posaka', 'iskon', 'chonka', 'pacha', 'waranka']
    if word.lower() in numbers:
        return 'NUM'
    else:
        return False
