In a five letter or digit password there are 1,679,616 possible combonations. My password was 15 characters long. That's 6,140,942,214,464,815 possible combonations with digits {A-Z, 0-9}.
Despite the fact miki was joking, this is rather interesting.
(forumula, 36 x 36 equals a 2 digit password, which is 1,296. Add up and get the numbers.)