How many root servers exist?

As a keen observer of the digital landscape, I'm curious to delve deeper into the infrastructure that powers our online world. Specifically, I'm wondering about the backbone of the internet's domain name system. So, I must ask, how many root servers actually exist? These servers, tasked with maintaining the master directory of all top-level domains, are crucial to the smooth functioning of the internet. Their redundancy and distributed nature ensure resilience and reliability, but just how many of these guardians of the digital realm are there?