Maximum number of clusters supported by mongodb?

We want to install 50 Servers with MongoDB, I want to know the necessary requirements?

When you want to operate MongoDB at scale you start to think in numbers of shards rather than numbers of servers. Each shard represents a single replica set with some number of replicas. Assuming you have N shards each shard can handle 1/N part of the load.

All this can be more easily managed by starting with our managed service MongoDB Atlas.

In our case we would have our own servers.