Numerical conversions

I'm trying to make a program that converts decimal to binary, octal and hexadecimal. My intention is to make a program that can convert "any" number, regardless of its size for these other bases.

My doubt in the case is: from decimal 1.10¹⁵ the program does not properly convert the value, why does this happen? In fact, if someone knows a better way to do it, and certainly has one, and can pass me, I would appreciate it.

#include <stdio.h>
#include <math.h>

int b=0,o=0,h;

void ConvertToBinary(long double n);
void ConvertToOctal(long double n);
void ConvertToHexa( long double n);


 int main() {
  long double x=0;
   printf("Valor na base Decimal:");

    scanf("%Lg",&x);

  printf("Em Binario: ");

  ConvertToBinary(x);

  printf("\nEm Octadecimal: ");

  ConvertToOctal(x);

  printf("\nEm Hexadecimal: ");

  ConvertToHexa(x);
  printf("\n");

  return 0;
   }

  void ConvertToBinary(long double n) 
 {
int i=0;
if(n == 0){
  printf("0");
}
else{
if ( n / 2 != 0) { 
    ConvertToBinary(  n / 2); 
}
if( b==0){      
  if( ((int) n%2) == 1){ 
    ++i;
  }
}
b = b+i; 
if(b >= 1){ 
printf("%d", (int) n % 2);
}
}
}

 void ConvertToOctal(long double n)
{
int i=0;
 if(n == 0){
printf("0");
 }
else{
if ( n / 8 != 0) {
  ConvertToOctal(  n / 8);
}
 if( o==0){
if( ((int) n%8) != 0){ 
  ++i;
}
}
 o = o+i;
if(o >=1){
 printf("%d", (int) n % 8);
 }
}
}


  void ConvertToHexa( long double n)
 {
 int i=0;
 if(n == 0){
printf("0");
  }
 else{
  if ( n / 16 != 0) {
  ConvertToHexa(  n / 16);
  }

  if( h==0){
   if( ((int) n%16) != 0){
    ++i;
    }
   }
   h = h+i;

  if(h >=1){
  if( (int)n%16 >= 10 ){
   switch ( (int) n % 16 )
  {
   case 10 :
  printf ("A");
   break;

   case 11 :
   printf ("B");
   break;

   case 12 :
   printf ("C");
   break;

   case 13 :
   printf ("D");
   break;

   case 14 :
   printf ("E");
   break;

   case 15 :
   printf ("F");
   break;
   }

    }
   else{
   printf("%d", (int) n % 16);
   }
   }
   }
   }