There is no simple answer to this. Most published contemporary novels are anywhere from 80,000 to 100,000 long. For some genres, like epic fantasy, 120k+ is not unusual. A lot of contemporary literary fiction can be very short, around 50k.
For the purposes of most literary prizes, 40,000 or more is sufficient to call the work a novel. Remember that there is no “official” word count per story-type or genre - just averages which can act as useful benchmarks.
Here’s a quick reference guide:
Epic (or Sage) | 110,000 or more |
Novel | 40,000 or more |
Novella | 17,500 to 39,999 |
Novelette | 7,500 to 17,499 |
Short Story | under 7,500 |
The average adult novel is typically around 73,000 words.