Bluebulb Projects' The Measure of Things presents:
660,000 is about three-and-a-half times the number of Letters in the Longest English Word.
In other words, it's 3.477 times the count of Letters in the Longest English Word, and the count of Letters in the Longest English Word is 0.287604 times that amount.
The longest word in the English language (although somewhat disputed) is a chemical name for the substance connectin, made up of 189,819 letters (Click here to see the word...). The longest word found in most dictionaries, pneumonoultramicroscopicsilicovolcanoconiosis, has just 45 letters.