How to print an unsigned long int with printf in C?

Possible Duplicate:
How to printf “unsigned long” in C?

I have my number like so...

int unsigned long number = 600851475143;

I am trying to print it with printf(). Every time I try, I get a warning by the compiler.

I've tried %uld, %ld and Googling hasn't seemed to find me the answer.

I'm learning C, but have not had to use a long int before, so I'm not sure what I should be using.

What is the specifier I am chasing?