Desmos factorial error

Question

Desmos gives an undefined value for the factorial function for integers greater than $169$ (which just so happens to be $13^2$). The reason is that desmos uses a 1024-bit system, and apparently, it thinks that $170!$ is greater than $2^{2^{10}-1}-1$, but it isn't. And to confuse you more, even though desmos this that $170!$ is incalculable, it can easily compute $169!×170$ ($7.2574×10^{306}$), which by definition is the same as $170$ factorial. Plus, $2^{2^{10}-1}-1$ is about $1.7977×10^{308}$, almost $25$ times the value of $170$ factorial. Plus, GeoGebra can do the same calculation, no problem. Can anyone tell me why this happens? Thanks a lot! :)