I pronounce it like 'rank', but I make clear it's written 'Rankk'.
It's funny, this has reminded me of people pronouncing 'Mari0' (the game mix between Mario and Portal) like 'Mario zero', 'Mari'O', 'Mario'... No agreement at all, hahaha... 
Steganographer and steganophile. INTJ-A. Checking what everyone takes for granted. Joking around. By the way, I love maths.