How to represent a binary number size greater than 64 bit

Question

I have a binary number which I want to represent in decimal. The number is as follows:

Binary = 1000 11100000 00000000 00000000 00000000 00000000 01101110 10110000 10100101  

Its equivalent hexadecimal representation is as follows :

Hexadecimal = 08 E0 00 00 00 00 6E B0 A5

I am working on Windows 7 and tried using calculator in programmer mode with Bin (Binary) and Qword. However, it has a limit of 64 bit.

Questions:

• How do I represent this number in decimal?
• Is there any free tool available to represent this number?
• Is there any way in C++11/C++ to achieve this?

Answer 1

First determine how large a binary number your platform will support. Let's say it's 64. Divide your binary number into chunks of 64 and do the low-order chunk as normal. Now, the low-order bit of the next chunk represents 2⁶⁴. Convert that chunk like a regular number but multiply it by 2⁶⁴. You could use this technique as many times as you need. The next chunk you would multiply by 2¹²⁸, then the next by 2¹⁹², etc.