node, 50 bytes

Result

AC

Code [DL]

with(require("fs"))write(1,readFileSync(0).sort())

stdin

2667707339560400678180098763706433105072373292370590542450984859824008371376557963663294641235896820

stdout

0000000000000001111222222222333333333333344444444555555555666666666666777777777777888888888999999999

stderr

(node:5) DeprecationWarning: Calling an asynchronous function without callback is deprecated.

strace