Any number that is greater than 1.
When 2 enemies are attacking you during a game of Halo 3, it is appropriate to say the following:
Person A: WHAT THE FUCK. A BAJILLION people just POPPED OUT OF NOWHERE and KILLED ME. Fucking N00BS.
Person B: ... There were like 2 people over there dude.
Person A: SHUT UP! Any number greater than one is a BAJILLION.