I would like to use base\_convert function to convert 60 bit binary data to Hex code as follows. But the result is not correct. The output of the code below is 4e08556312ffc00 but the correct output is 4E08556312FFBFF. 
Can anybody tell me why? is 60 bit too large to the function? 

```
echo "The beacon ID in Hexadecimal is".base_convert
         ("010011100000100001010101011000110001001011111111101111111111",2, 16);

```

Thank