Thread: printing out bit values without using an array

I wrote a code that requests user input and then converts binary to bcd then back to binary using bitwise operations.
While I think my code is good I want to know if there is a better way to write the code.
Is there also a way to keep the code mostly the same but getting rid of the arrays for printing out the bit positions?

Code:

    #include <stdio.h>
    #include <limits.h>
    #include <stdlib.h>
    #include <string.h>
    
    
    #define UINT_MAXIMUM 4294967294
    #define MAX_NUMBER 99999999
    
    void printBits(unsigned long number);
    unsigned long convertBinaryToBCD(unsigned long number);
    unsigned long convertBCDToBinary(unsigned long number);
    unsigned long printNumber(unsigned long input)
    {
      printf(" Input: ");
      printf("%10lu", input);
      printBits(input);
      unsigned long output_bcd = convertBinaryToBCD(input);
      unsigned long  output_binary = convertBCDToBinary(output_bcd);
      printf("   BCD: ");
      
      if(output_bcd != UINT_MAX)
      {
        printf("%10lu", output_bcd);
        printBits(output_bcd);
      }
      printf("Binary: ");
      if(output_binary != UINT_MAX)
      {
        printf("%10lu", output_binary);
        printBits(output_binary);
      }
      return 0;
    }
    void printBits(unsigned long number)
    {
        int bit_position[32];
        printf(" - ");
        int counter = 0;
        for(counter = 32; counter > 0; counter--)
        {
            bit_position[counter] = number % 2;
            number = number / 2;
        }
        for(counter = 1; counter <= 32; counter++)
        {
            if(counter == 9 || counter == 17 || counter == 25)
            {
                printf(" | ");
            }
            if(counter == 5 || counter == 13 || counter == 21 || counter == 29)
            {
                printf(" ");
            }
            printf("%d", bit_position[counter]);
        }
        printf("\n");
    }
    
    int main(int argc, char *argv[])
    {
      unsigned long number;
    
      number = strtoul(argv[1], NULL, 10);
    
      if(number > UINT_MAXIMUM)
      {
        printf("too big\n");
        return 0;
      }
      printNumber(number);
    
      return 0;
    }
    
    unsigned long convertBinaryToBCD(unsigned long number)
    {
      if (number > MAX_NUMBER)
      {
        return UINT_MAX;
      }
      if(number < 100)
      {
          return (((number/10)+((number/100)*6))*16)+(number%10);
      }
      unsigned long sub_number_one = ((number / 12) << 5);
      unsigned long sub_number_two = (number % 10) ;
      unsigned long temporary;
      while(sub_number_two != 0)
      {
          temporary = sub_number_one & sub_number_two;
          sub_number_one = sub_number_one ^ sub_number_two;
          sub_number_two = temporary << 1;
      }
      return sub_number_one;
    }
    
    unsigned long convertBCDToBinary(unsigned long number)
    {
      if (number == UINT_MAX)
      {
        return UINT_MAX;
      }
      if(number < 100)
      {
          return (((number >> 8) * 100) + ((number >> 4) * 10) + (number & 0xF));
      }
      
      unsigned long sub_number_one = (number >> 8) * 100;
      unsigned long sub_number_two = (number & 0x0F);
      unsigned long temporary;
      while(sub_number_two != 0)
      {
          temporary = sub_number_one & sub_number_two;
          sub_number_one = sub_number_one ^ sub_number_two;
          sub_number_two = temporary << 1;
    
      }
      return sub_number_one;
    }