Download ntob.tgz
$ ./ntob -h
ntob, version 1.01
usage: ./ntob -o <output base> -n <input value> [-i <input base>] [-h]
N to Base: Convert a number from one base to another. Bases can be anything from 2 to 36.
Input base defaults to 10. Bases beyond 16 use the alphabet as you'd expect.
Examples:
$ ntob -o 2 -n 10 # convert 10 to binary
1010
$ ntob -o 10 -n 1010 -i 2 # and back
10
$ ntob -o 8 -n 10 # convert 10 to octal
12
$ ntob -o 16 -n 10 # base 16 A is equal to decimal 10
A
$ ntob -o 36 -n 35 # base 36 Z is equal to decimal 35
Z
$ ntob -o 36 -n 1767707668033969
HELLOWORLD