What is the Number of epochs with no improvement after which training will be stopped.?
The number of iterations with no improvement is a hyperparameter. Scikit-learn has a default value of 10 in the MLPClassifier but of course you can select one depending on your problem. You can also do a grid search over all your model's hyperparameters.
Another advice I would give is that you could first train the model experimentally for a lot of epochs. If you see it getting stuck for a lot of iterations and then increasing after a halt, then it's better to set a higher value. On the other hand if after a lot of time you don't see it improving you should set the max number of iterations with no improvement to a smaller value.