Presuming you're noting exponentiation with ^, 4 billion ^ 4 billion addresses would mean 128 gigabits per address. IPv6 addresses don't take up half a gigabyt

Presuming you're noting exponentiation with ^, 4 billion ^ 4 billion addresses would mean 128 gigabits per address. IPv6 addresses don't take up half a gigabyte each in any sane encoding. IPv6 has 128-bit addresses, which works out to about 4 billion ^ 4 addresses, not 4 billion ^ 4 billion addresses.