eyeint (ii) is a command line app to inspect arbitrary sized integers with various settings.

eyeint has the following features:

• Inspects integers with an arbitrary number of bits (up to 64)
• Converts arbitrary radix (2-36) integers into most common integer radices
  • binary
  • octal
  • decimal
  • hexadecimal
• Handles signed integers
• Truncates and (sign/zero) extends integers with arbitrary bit precision
• Shows information about an integer's two's complement