In real world its advised not to stack more than 6 switches together of any platform
http://www.cisco.com/c/en/us/products/collateral/switches/catalyst-3650-series-switches/q-and-a-c67-729531.html
Cisco have in docs 9 Feature
Cisco Catalyst 3650 Cisco Catalyst 3850 Stacking bandwidth/max members in stack 160G/9