The number is 0.

Max all
Upgrade 1st button.
Cost: 100
Level: 1

You have 0 autobuyer levels.
Autobuyer interval is 1000ms.
you keep automation if you have >20TP/PP
Upgrade autobuyer 1 for 10000.
next layer: 1e100 number and maxed automation

Gain 0 tetration points, but
reset button levels and number, as well as increasing cost.
You have 0 tetration points, tetrating income by 1.

Upgrades
Multiplier to production based on TP
Cost: 7 TP
Not bought!
Gain 100% of TP on reset each second,
but remove the option to Tetrate.
WARNING: Resets TP when bought
Currently: 1/sec.
Cost: 1000 TP
Not bought!
if you have the 2nd tetration upgrade,
click me to speed up the grind
(gain +1% TP)

next layer: ~1e10TP

Gain 0 pentation points, but
reset everything below Pentation.
You have 0 pentation points, pentating TP effect by 1.

Upgrades
Multiplier to TP based on PP
Cost: 7 PP
Not bought!
When Pentating, you keep Tetration upgrades. always keep automation
Cost: 50 PP
Not bought! Gain 1% of PP each second,
but remove the option to Pentate.
WARNING: Resets PP when bought
Cost: 10000 PP
Not bought!
e10 PP is the endgame