If you have an integer value, and you want to print it just do the following (in C):
int number = 555;
printf("%d",number); //this prints number in decimal
printf("%x",number); //this prints number in haxadecimal
You must not forget, to a machine, there are only 0's and 1's.
You just have to define the way you want to print it
In C++:
int number = 555;
std::cout << std::hex << number << std::endl; //this will print the number in hexadecimal