Trying to understand why this happens

[Griffith]

#include <stdio.h>

void calculateTriangularNumber (int n)
{                                       
    int i, triangularNumber = 0;

    for (i = 1; i <= n; ++i)
        
        triangularNumber += i;
    
    printf ("Triangular number %i is %i\n", n, triangularNumber);
}

int main (void)
{
    int n;
    
    printf ("What triangular number do you want to calculate?\n");
    scanf ("%i", &n);
    
    calculateTriangularNumber (n);
    
    return 0;
}

Hi, this is my first post here and im starting to learn C. So this code is for calculate the nth triangular number. Everything works fine but my question is why, when I must put what triangular number I want to calculate, but I write a char or string like the letter a or any word the program return "Triangular number 32764 is 536756230? I want to know why this happens. Cause I declare n to be an int. And how can this be fixed. Thank you

[christophergray]

Everything stored in the computer is just a bunch of bits turned on or off. Whether it is a letter or number is just a matter of interpretation. You have told scanf to see the bits as an int, and it has obeyed.