After reading an article about factorial number system. It tells that you can present any number in a factorial system and in if you have a number $a_{n-1}...a_2a_1a_0$ in factorial number system, you can transform it to decimal as $\sum_{i=0}^{n}i!\cdot a_i$.
Nonetheless I found it really cool, I can not find a lot of applications of such a system beyond:
- finding n-th lexicographical permutation (which is highlighted in the wiki)
- big numbers can be represented with smaller number of digits (number higher than 25!)
Are there other applications of this number system?