What is the number of bits of an IP address in IPV6 version?

While IPv4 uses 32 bits (allowing for about 4.3 billion addresses), IPv6 was designed to solve the problem of address exhaustion by using a much larger 128-bit address space.Why 128 bits?To put that number into perspective, $2^{128}$ provides approximately 340 undecillion addresses. That is enough to assign an IP address to every atom on the surface of the Earth and still have plenty left over.