mathematics - What is the "linguistically hardest" number less than $10^9$?

The linguistic hardness ($LH$) of a natural number is the ratio of the amount of letters in the writing of this number in English to the amount of its digits.

For example, $LH(1234) = 7.75$, as:

$$\frac{\mbox{Number of letters}}{\mbox{Number of digits}} = \frac{\mbox{N(one thousand two hundred thirty four)}}{N(1234)}= 31/4 = 7.75$$

What the is $N: 0

P.S. This puzzle appears to be much more interesting in Russian, but this is not Russian site to ask it here.

Answer

For any given digit range the numbers with the longest spelling have the highest LH.

7-only-combinations are always among those numbers. Here's a table with their corresponding LH:

 number from here | number segment | letters from here | LH
------------------+----------------+-------------------+-------
        777777777 | seven hundred  | 87                | 9 2/3 = 9 14/21
         77777777 | seventy        | 75                | 9 3/8
          7777777 | seven million  | 68                | 9 5/7 = 9 15/21
           777777 | seven hundred  | 56                | 9 1/3
            77777 | seventy        | 44                | 8 4/5
             7777 | seven thousand | 37                | 9 1/4

              777 | seven hundred  | 24                | 8
               77 | seventy        | 12                | 6
                7 | seven          | 5                 | 5

Looks like 7777777 beat my previous suggestion. It worries me that LH(8878878) is the same (alongside others like 3878373).