How many neighbours does a Node have? I'm writing a blockchain simulator to evaluate the bitcoin network and currently running some evaluation experiments. 

I couldn't find a reference for the approximate number of neighbour each Node has in its table. 

Can anyone point me to a source?
It is impossible to know how many nodes each node is connected to or has in its peers table. This information is not broadcast publicly and the information that is available publicly (by asking a node) is not representative of what the node actually knows.