My book's title is similar to Around the World in 80 Days. The premise is making a journey in 80 days and while I am sure that using a similar premise is fine (especially since my book is a bit of a satire on lots of common premises). Is it legal to use a similar title?
** Disclaimer ** I'm not a legal expert so my first advice would be to consult a lawyer.
For my answer, I would say it depends on how close the title to the original and how obvious it is that the book is a parody.
Doing a quick Google search, there are plenty of books with similar titles to existing titles but which are obvious spoofs (my favourite so far being "The Very Hungover Caterpillar" but even the cover of this says "A Parody" on it) and if you're poking fun at an existing genre, then the more stereotypes you can bring into it, the better.
It is legal to use the same title, but I would still make it a variant of the original to avoid confusion.
The book is out of copyright, so you can do pretty much whatever you want to it.