Autobiographical number

Yeah sounds weird doesn't it...

It is a number with ten digits or less with the first digit (from the left) indicating the number of zeros it contains, the second digit the number of ones, the third digit the number of twos and bla bla bla...

One would think...well if its a number with a maximum of 10 digits, well we can have a large number of autobiographical numbers. NO! there are only 7 of them. Now, you could try finding which ones they are. I mean..7 only and you have the clues of how the digits in an autobiographical number are arranged. How hard can it be??

I'll give you the smallest and the largest autobiographical numbers as a sort of clue

The smallest autobiographical number is 1210 and the largest, 6210001000

:)

good luck!