None. Because that, and the majority of Dell prebuilt systems, use proprietary power supplies with proprietary connectors.
Yes, there are ways to "mod" them, and there are adapters out there, but often you will still run into problems with them not fitting because the form factors are different and there just isn't room in those cases. And if you think to move the system into a different case, forget it, because the motherboards are proprietary too and without serious modification, won't work in a standard form factor case.
If you check the Dell forums, you'll find threads like this one, but honestly, most of them are simply BS methods that end up in frustration and angst, and users usually just ditch it and start over due to the overwhelming PITA that is involved in trying to make them work. It can be done, but it's usually painful.
https://www.dell.com/community/Inspiron-Desktops/Inspiron-3670-PSU-upgrade/td-p/6117898
Again, it can work in some cases, but in others, they end up with unsatisfactory solutions like an adapter and the PSU outside the case.