You will obviously need big integer arithmetics extension.
tupper.sm (204.5 KiB) downloaded 900 time(s).
tupper.sm (202.26 KiB) downloaded 903 time(s). (revised)

You will need Big Integer Arithmetics plugin.
You can install it from SMath>Tools>Plugins.

Wikipedia page for information about formula:
https://en.wikipedia.org/wiki/Tupper%27s_self-referential_formula

You can create your own tupper number with this site:
https://tuppers-formula.ovh/