#include<string.h>

int main() {
   int number1, number2;
   char str[10];

   printf("\nEnter a Number:::");
   scanf("%d", &number1);

   sprintf(str, "%d", number1);//step 1
   strrev(str);//step 2
   number2 = atoi(str);//step 3

   printf("\n Reverse of the number:::");
   printf("%d", &number2);

   return 0;
}

OUTPUT:

Enter a Number ::: 1234
Reverse of the number::: 4321

Explaination of above code:-

1. Storing the number into Form of String:-

   sprintf() function sends formatted "number1" to string variable "str".

2. Using strrev() function to reverse the string "str"

   eg 1234 will be reversed as 4321

3. Convert String to Number using atio() function:

   atoi() stands for "Alphabet to Integer". This function converts "String to Integer".