Sharepoint 2013 Sub Site limit

Hi,

I have an requirement, where I want to create SharePoint site for each project, which will end up near about creating 8000 sub sites under my site collection.

Is it Ok to create these many number of sub sites, what is the safest number ?

Also,  each of the sub site will have couple of works flows, so when it comes with updating site overnight. which is safest number that SharePoint can handle.