exponent

# File activesupport/lib/active_support/number_helper/number_to_human_size_converter.rb, line 44
        def exponent
          max = STORAGE_UNITS.size - 1
          exp = (Math.log(number.abs) / Math.log(base)).to_i
          exp = max if exp > max # avoid overflow for the highest unit
          exp
        end