(2-part post):
0 is a member of the set of integers and thus, by definition, finite rather than infinite.
Mathematicians don't recognise 'infinity' as a 'number'. The result of dividing anything by zero is simply referred to as 'not defined'. Alternatively, they state n�x tends to infinity as x tends to zero.
Here's an example of why one 'infinity' isn't (contrary to initial appearances)bigger than another one:
Start with the list of all the integers, i.e.
. . ., -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, . . .
Since the list goes on forever (in both directions), there are clearly an infinite number of integers in the set.
Now lets remove every other number from the list. So, if we remove the odd numbers we get this:
. . .-6, -4, -2, 0, 2, 4 6, . . .