The other party hacked my number. Can he still see it if I text him?

It can only be said that the other party can receive it, and it is in the intercepted message. As for whether the other party can see it, there are the following possibilities:

If the other party has set interception and reminder, the other party can know the information you sent.

If there is no reminder, then the mobile phone will not respond and directly enter the intercepted SMS. If the other party takes the initiative to check, you can see it; If you don't take the initiative to check, you won't know