Device info phone number and 18.0 installation

Recently, I tried to install 18.0 on this pad but failed due to lack of memory, 3GB short of space, now i see It has updated on its own, How?

Whose phone number is on my ipad? While checking DEVICE INFO I came across a “Phone number 1+(619) *** ***” not mine, so I called this number with my phone, a guy answered and when i asked him who he was he hung up!

Is this some hacker who installed 18.0 and 18.1 to take control or access of my ipad?

[Edited by Moderator]