1. IP v6 Address Space four time the # of bits as v4 # of addresses:
128 bit vs 32 bit
# of addresses:
340,282,366,920,938,463,463,374,607,431,768,211,456

2. Size Address space > 3.4 x 1038
This is approximately 665,570,793,348,866,943,898,599 addresses per square meter of the surface of the planet Earth (assuming the earth surface is 511,263,971,197,990 square meters).

3. OR…
If addresses are assigned at the rate of one million address every microsecond, it would take over 20 years to assign all possible address.