Code:
```#include <stdio.h>
#include <math.h>

void test(const int aIntNumber)
{
// Test for divisibility
if(aIntNumber % 7 == 0||
aIntNumber % 11 == 0||
aIntNumber % 13 == 0)
{
printf("\n%d is divisible!\n", aIntNumber);
}
else
{
printf("\n%d is not divisible!\n", aIntNumber);
}

// Calculate the sum of the digits
int anotherIntNum = aIntNumber;
int sumOfDigit = 0;
while(anotherIntNum > 0)
{
sumOfDigit += anotherIntNum % 10;
anotherIntNum = anotherIntNum / 10;
}
sumOfDigit += anotherIntNum;
// Test if the sum of digits of number is even or odd
if(sumOfDigit % 2 == 0)
{
printf("\nsum of digits in %d is even\n", aIntNumber);
}
else
{
printf("\nsum of digits in %d is odd\n", aIntNumber);
}
// Test if the number is prime or not
int s = (int)sqrt((double)aIntNumber);
if(aIntNumber > 0 && aIntNumber < 4)
{
printf("\n%d is prime!\n", aIntNumber);
}
else if(aIntNumber < 0)
{
printf("\n%d is not a natural number!\n", aIntNumber);
}
else if(aIntNumber > 4)
{
for(int i = 4; i < s; i++)
{
if(aIntNumber % i == 0)
{
printf("\n%d is prime!\n", aIntNumber);
return;
}
}
printf("\n%d is Not prime!\n", aIntNumber);
}
else
{
printf("\n%d is Not prime!\n", aIntNumber);
}

}

int main(int argc, char* argv[])
{
test(13);

return 0;
}```