What does the SMS center number mean? What's the role?

It can be used for number authentication. For example, if you send a text message to this number, this number will be sent to the person you want to send, similar to a server. Personally, if the number is changed, the transmission will fail. I used to play a game where I needed to send text messages when I bought things. If I changed this number, I couldn't send text messages without deducting money.