If you like playing with those numbers also consider that private keys in modern wallets are generated from word lists of length 12.
If those words were used as an alphabet then they would define a 2048^12 or 132 bit key space.

The word lists are instead hashed (see BIP39) which gives an approximate entropy of 2.62*4.5*12 = 141 bits.

Therefore the attainable private key set in modern wallets is smaller than the 160 bit range of addresses.

Using entropy estimates from here: http://people.seas.harvard.edu/~jones/cscie129/papers/stanford_info_paper/entropy_of_english_9.htm