Find a ten digit number, such that the first digit in that number is the number of ZEROs in the entire number, the second digit in that number is the number of ONEs in the entire number, the thrid digit is the number of TWOs in the entire number, and so on, until the tenth digit, which is the number of NINEs in the entire number.

Don't google it! Do it on your own, you'll like it. This is quite an interesting one if you haven't done it before.

One hint I can give you is, that if you take any ten-digit number and start applying the above 'rule' to it, you'll eventually arrive at the correct answer.

Of course, it all depends upon which number you choose to start from.