Do you have any idea how many nodes are currently running right now?
There are 58 mining nodes running at the moment out of the total 75 validated addresses:
https://scan.idena.io/#minersand what is the basic hardware requirement running the node?
I have a PC right now with 8 Gb ram and I am using this computer for 12 hours/day, I would like to run one of the nodes if it is possible using my personal computer.
That's fine for running the Idena node.