I'd say that at that length you could pick whether you wanted to call it a novella or a novel.
However, if you publish it as a novel, then you might want to make sure that it has the estimated page count or a similar disclaimer/explanation regarding length. That way, people who only want War & Peace size novels know what to expect!
As Patrick said above, according to the rules of Nebula Awards, the Science Fiction and Fantasy Writers of America (SFWA is the correct abbreviation, despite the two Fs) considers a novella to be 17,500 - 40,000 words.
40,000 and above is novel territory.
However, this designation is more flexible in the world of other genres or general fiction.
Also, since the popularization of NANoWriMo, many consider a novel to be 50,000 and above.
In the 1980s and 90s, I read The Destroyer series of novels. They were often under 300 pages, which would put them in the mid 40,000s. I think these giganto novels of today are a fairly recent invention.