Can you find out which number multiplied by itself will give the output as 12345678987654321?

A high school has a strange principal. On the first day, he has his students perform an odd opening day ceremony:

There are one thousand lockers and one thousand students in the school. The principal asks the first student to go to every locker and open it. Then he has the second student go to every second locker and close it. The third goes to every third locker and, if it is closed, he opens it, and if it is open, he closes it. The fourth student does this to every fourth locker, and so on. After the process is completed with the thousandth student, how many lockers are open?

I am lying and I always lie. Tell me whether I am lying or telling the truth.

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

Can you write down eight eights so that they add up to one thousand?

What is so fragile that saying its name breaks it?

Can you find a number that lies one third of the distance between 1/3 and 2/3?

Yesterday I fell from 30 feet high ladder but I don't get hurt. Why?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

If 24H in a D => 24 hours in a day.
What does "64S on CB" stand for?