Long time no see" is an expression so it does not need to be literal ( you can say it without actually seeing someone with your eyes). You can as stated above, say : It's been ages/along time/forever since we talked. We havnt talked in ages.

We have a common expression: "Long time no see/talk," which would work here. To more literally answer you question, you could say, "It's been a long time since we talked," or, "It's been awhile since we last talked."

"Long time no see" is commonly used when you haven't seen or talked to someone in a while.

I wouldn't say ''long time no talk to you''. I would say "it's been a while" or "it's been forever"

Good: We haven't talked in ages this English speaker agrees. common idiom.