#2484·calculator

binary logarithm of a factorial larger than 30! outputs "0" or "Result is undefined"

Author: henshingattaiCreated Jul 2, 2026Updated Sep 10, 2026

Describe the bug

when you enter a number and press exclamation point, you get the factorial, then you should be able to press "2nd" and then the number "2" and the equal sign, you get back how many bits you need to represent that factorial.

Steps To Reproduce

"512" "!" "2nd" "Log yX" "2" "="

Expected behavior

should not say "Result is undefined" or "0", but a normal number.

Screenshots

Device and Application Information

  • OS Build: Major Minor Build Revision

10 0 26200 0

  • Architecture: X64
  • Application Version: 11.2605.9.0
  • Region: en-US
  • Dev Version Installed: False

Additional context

it worked perfectly in the earlier versions, but I don't know when automatic updates actually triggers at the moment, so I don't know how many versions may have released since the error was introduced.

Requested Assignment

I'm just reporting this problem. I don't want to fix it.