According to Netcraft [0] there are currently 171,432,273 active websites. However there were 1,436,724,046 host names on the net. A total of 6,225,374 web-facing computers was reported.

Interestingly the number of active sites hasn't materially changed in 5 years, but host names have skyrocketed.

[0] https://news.netcraft.com/archives/category/web-server-surve...