The address you observe is located in the Procedure Linkage Table (PLT). This mechanism is used, when the location of an external (dynamically linked) symbol is not known at the time, when your binary is compiled and linked.
The purpose is, that the external linkage happens only at one place, the PLT, and not on all places throughout your code where a call to the symbol happens. So, if printf() is called, the way is:
main -> printf@PLT -> printf@libc
At runtime, you cannot find out easily in which external library the function you call is located; you would have to parse the opcodes at the destination (the PLT), which usually fetches the address from the .dynamic section and jumps there, then look, where the symbol is really located and finally, parse /proc/pid/maps to get the external library.