the maximum number of documents in an elasticsearch index and difference about stats and count

Elastic Stack Elasticsearch
1

I have an index in elasticsearch with only 1 primary shards e 0 replica.
When I do GET /index/_count, the result is 100,815.
When I do GET /index/_stats, the result is 64,893,983. Each doc has nested fields.
My question is: what number do I have to consider for the limit Number of documents in the index can't exceed [2147483519]?

In case of the second one number, do you suggest to increase the number of primary shards? I have only one pc.
Thank you

2

Yes, I believe you need to include nested documents in the count. In order to increase the number of primary shards you will need to either use the split index API to create a new index based on the existing one or reindex into a new index.

Not that the limit is per shard and not index (as stated in your title).