The number of words in a book depended on many factors such as the author, the subject matter, the story structure, the style of writing, and so on. Moreover, the length of a novel also varied greatly. It could range from tens of millions of words to millions of words. Generally speaking, a medium-length novel of about 500,000 words would usually contain a complex storyline and some rich characters and conflicts. A longer novel, such as one million words or more, might contain more plot details and more complicated character relationships. It is important to note that word count is not the only factor in evaluating the quality of a book. Other factors such as plot, writing style, plot twists, character portrayals, etc. are equally important. Therefore, the word count of a book should be evaluated based on multiple factors.