Q:

Print multiple characters, formatted as an integer

Whenever I run this program, It gives output 12592. 
I couldn't find the logic behind it.  It it in C Programming. 
#include <stdio.h>

int main()
{

    printf("%d",'10');

    return 0;
}

A:

'10' is actually a multi-character constant. 
It has a type int, just like say '1', but its actual value is implementation defined. 
Quite feasibly its value is '1' * 256 + '0' which is 12592 on your platform which is, from what I can tell, using ASCII encoding.