def pretty_print_large_number(number):
    """Given a large number, it returns a string of the sort:  '10.5 Thousand' or '12.3 Billion'. """
    s = str(number).ljust(12)
    if number > 0 and number < 1e3:
        pass
    elif number >= 1e3 and number < 1e6:
        s = s + "  (%3.1f Thousand)" % (number * 1.0 / 1e3)
    elif number >= 1e6 and number < 1e9:
        s = s + "  (%3.1f Million)" % (number * 1.0 / 1e6)
    elif number >= 1e9 and number < 1e12:
        s = s + "  (%3.1f Billion)" % (number * 1.0 / 1e9)
    elif number >= 1e12 and number < 1e15:
        s = s + "  (%3.1f Trillion)" % (number * 1.0 / 1e12)
    return s