For reference purposes only — no wagering! — Steph Mineart lists 161 famous short stories, in ascending order of length. (Shortest one listed: Virginia Woolf’s “A Haunted House,” a breezy 710 words.) The average: a hair over 4000 words.
She’s also done a list of word counts for famous novels, and no, War and Peace (587,287 words) isn’t the longest.
And I note with no small degree of angst that I have written nearly four million words in the last five and a half years — 55,000 just in January — but I seriously doubt I could put together a decent 4000-word short story. (Although this isn’t too awfully bad for 300 and change.)