There seems to be some confusion since you are looking at the encoded version of the Bitcoin address.
There are exactly 2160 possible addresses as long as we keep using RIPE-MD160.
2160 is 1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976.
We don't have to guess at this by looking at the ASCII encoded values (the human readable form you are seeing).
Do you often worry that someday all of the oxygen molecules in the room you are in will spontaneously drift away from the part of the room you are in and you would die? After all, that could happen, right? It is not impossible, right?
That should be a bigger worry for you than running out of Bitcoin addresses.
I am wondering where you go tthe 2 from in that equation
An 160 bit number is a sequences of 160 binary digits, expressed as a base 2 number. The 2 comes from the fact that base 2 is the type of number system what's being used. In the mathematics of permutations and combinations, you resolve the number of combinations by taking the number of possibilities in a given position as the mantissa, and the number of positions as the exponent.
Hence, the number of possible combinations given a set of base 2 numbers with 160 positions is 2
.