alternate size tire for a 700 x 44c

[Rothed1]

Son got a good deal on an Alton brand Electric road bike here in Korea. Rear tire has popped multiple times in the few weeks he has had it. After replacing four tubes and not finding anything but dings and scrapes on the rim, I am looking to try out a replacement tire. Problem I am running into is that the tire size is 44 x 622 / 700 x 42c, all of which it turns out is a rare size. Is there a suitable size tire that is more standard/available?

Appreciate any help or guidance.

/r
Wayne