The cluster of galaxies that contains the Milky Way is called the Local Group.

While it contains over 50 galaxies, the largest members are the Milky Way, Andromeda (M31), and Triangulum (M33).

It's important to note that the number 25 you mentioned is not quite accurate. While the Local Group is estimated to have over 50 galaxies, the exact number is still under debate due to the difficulty of identifying and classifying smaller, fainter galaxies.