Convert a number from one base to another base in C

#include < stdio .h=""> 
long convertInBase10 (long n, int base)
{
 long quotient = n / 10; 
 remainder = n % 10; 
 if (quotient == 0)
 return remains; 
 else
 return convertingBase10 (quotient, base) * base + remainder; 
}
long convertEnBase2 (long n, int base)
{
 long quotient = n / 2; 
 remainder = n % 2; 
 if (quotient == 0)
 return remains; 
 else
 return convertEnBase2 (quotient, base) * base + remainder; 
}

long convertInBase4 (long n, int base)
{
 long quotient = n / 4; 
 remainder = n % 4; 
 if (quotient == 0)
 return remains; 
 else
 return convertenBase4 (quotient, base) * base + remainder; 
}

long convertInBase8 (long n, int base)
{
 long quotient = n / 8; 
 long remainder = n % 8; 
 if (quotient == 0)
 return remains; 
 else
 return convertenBase8 (quotient, base) * base + remainder; 
}

long convertInBase16 (long n, int base)
{
 long quotient = n / 16; 
 long remainder = n % 16; 
 if (quotient == 0)
 return remains; 
 else
 return convertingBase16 (quotient, base) * base + remainder; 
}

int main() {
 long n = 17; 
 int base = 10; 
 //Decimal --> base(2,4,8,16)
 printf ("%ld to base %2d = %ld to base 2\n",n, base, convert to Base2 (n, base); 
 printf ("%ld to base %2d = %ld to base 4\n",n, base, convert to Base4 (n, base); 
 printf ("%ld to base %2d = %ld to base 8\n",n, base, convert to Base8 (n, base) ); 
 printf ("%ld to base %2d = %ld to base 16\n",n, base, convert toBase16 (n, base); 
 
 //Binary --> Decimal
 n = 1010; 
 = 2; 
 printf ("%ld to base %2d = %ld to base 10\n",n, base, convert to Base10 (n, base); 
 
 //hexadecimal --> Decimal
 n = 124; 
 = 16; 
 printf ("%ld to base %2d = %ld to base 10\n",n, base, convert to Base10 (n, base); 
 
 //base 8 --> binary
 n = 12; 
 = 8; 
 printf ("%ld to base %2d = %ld to base 10\n",n, base, convert to Base10 (n, base); 
 
 return 0; 
}