Issue generating larger random numbers in PHP

In PHP, trying to use rand to generate random numbers between 0 and an 11 digit number.

rand (0 , 46938003261)

Unfortunately, the largest numbers I'm generating are only 9 digits, despite the 11 digit number I set as the max.

I realize this is a limitation of PHP on 32 bit systems, and I've had the same issue with mt-rand.

How can I generate a random number between 0 and 46938003261 with PHP?

Thanks!