Would it be called statistic, if it is said that there are 2000 students in the school

2 answers

Yes. It's a number representing an item of information.

http://www.merriam-webster.com/dictionary/statistic
Yes, I think so. It's a number that can be used to compare or contrast with other numbers in a variety of ways.

If it's a school that has capacity for 1,500 students, but there are 2,000 students, what conclusions can you draw?

If it's a school that has capacity for 3,000 students, but there are 2,000 students, what conclusions can you draw?

What other comparisons or contrasts can you think of?