There are 3.4×10^38 or 340 undecillion IPv6 addresses. It would take three times the age of the universe to actually scan all the IPv6 addresses on a 48 bit IPv6 subnet if you were scanning at a million addresses per second.
Similarly one may ask, what is the maximum possible number of IPv4 addresses?
IPv4 uses 32-bit IP address, and with 32 bits the maximum number of IP addresses is 232—or 4,294,967,296. This provides a little more than four billion IPv4 addresses (in theory). The number of IPv4 available addresses is actually less than the theoretical maximum number.
How many IP's are there in the world?
With IPv6, everything can have a unique number, making it easier and quicker for data to find its way around the Internet. In comparison to IPv4's 4.3 billion IP addresses, IPv6 can assign about 340 trillion trillion trillion (that's not a typo).
How many IP's are in a 24?
There are 256 actual addresses, but the 0 and 255 host addresses are not usable giving you only 254 usable addresses. the .255 is used as the broadcast address, anything addressed to that address should be answered by all devices in the same IP Block.