Well, determining the exact number of DC Comics issues is quite a challenge. DC has a rich history of publication, and new comics are added all the time. It's a vast and dynamic library that's hard to quantify precisely.
It's hard to give an exact number because new comics are constantly being added and some might be removed. But there are thousands of titles available.
DC Universe Rebirth graphic novels have brought back the sense of hope and legacy. They reintroduced classic elements that were lost in previous reboots. For example, the return of beloved character relationships.
To be honest, the number of issues can vary depending on the series' popularity and the publisher's plans. You could try looking on comic-related websites or asking in comic enthusiast communities for the latest and most accurate number.
The number of issues in the DC graphic novel collection can change over time as new ones are released. Your best bet is to do a detailed search on comic book databases or contact DC's customer service for the latest and most accurate information.