We don't know the exact number of planets in the Andromeda galaxy. However, we can make some educated guesses based on what we know about our own Milky Way galaxy:

* Planets are common: Astronomers have discovered thousands of exoplanets in our galaxy, and the evidence suggests that planets are common around stars.

* Andromeda's size: Andromeda is about twice the size of our Milky Way, so it's likely to have significantly more stars.

* Extrapolation: Based on the proportion of stars with planets in our galaxy, we can estimate that Andromeda could have *trillions* of planets.

It's important to note:

* We can only detect planets directly around nearby stars. Detecting planets in Andromeda is incredibly difficult due to its vast distance.

* Our current methods of detecting exoplanets (like the transit method) are biased towards larger planets close to their stars.

* The number of planets in Andromeda is likely to be much higher than what we can currently detect.

So, while we don't have a precise number, it's safe to say that Andromeda likely harbors a vast number of planets, possibly even trillions.