Some years ago, after I'd written the first couple stories in what was to become the Arenoso Trails series, and before I had considered posting my stories anywhere, I did some research on the word count of American novels. With my first two efforts ending up with 105K and 158K words, I was surprised to learn the the generally-accepted dividing line between a short story and a novel was about 50K words. Most of Louis L'Amours books, as are many modern western genre novels, are in that range. The contemporary custom for most published American novels in the adventure and mystery genres range from 90K to 150K words, with 120K being the sweet spot, though any number of popular novels are much longer.
However, it seems that word count isn't the only factor in a story's popularity. Go figure. I'm guessing spelling and punctuation may factor in, because most novels I've read have been pretty clean that way. I'm also guessing that the story and writing style may be important, but that's just one man's opinion.
Of course, nothing about word counts are rules or even guidelines. They're simply the result of current writing and publishing practices, and they vary over the decades. Here are a few just for reference. Counts can vary by edition and source:
The Adventures of Tom Sawyer, 70,570
Harry Potter and the Sorcerer's Stone, 76,944
The Hunt for Red October, 151,091
The Da Vinci Code, 144,330
The Great Gatsby, 47,094
Gone With the Wind, ~418,000
The Lord of the Rings, 564,187
To Kill a Mockingbird, 100,388
Fifty Shades of Gray, 155,749
The Old Man and the Sea,.~27,000
Of Mice and Men, ~30,000
Slaughterhouse-Five, ~49,000
True Grit, ~70,000
Lonesome Dove, ~120,000
The Man Who Shot Liberty Valance, ~50,000
Shane, ~65,000
Oh, yeah. My point was to mention that I'm 25K words into Del Norte, the fourth book in the Seneca trilogy and, as per usual, aiming for about 120K words. Results may vary.