import re

def unit_prefix(number):
    """Format big number by using unit prefixes"""
    if number >= 1000000000:
        if str(number).count('0') >= 9:
            return re.sub(r"000000000$", "G", str(number))
        else:
            return str(number/1E9) + 'G'
    elif number >= 1000000:
        if str(number).count('0') >= 6:
            return re.sub(r"000000$", "M", str(number))
        else:
            return str(number/1E6) + 'M'
    elif number >= 1000:
        if str(number).count('0') >= 3:
            return re.sub(r"000$", "k", str(number))
        else:
            return str(number/1E3) + 'k'
    else:
        return str(number)

print("{0:<20s} {1:>4d} files with {2:>4s} entries"
      .format(some_string, integer, unit_prefix(integer)))