Huh. He's kind of like an android in that sense, isn't he? As long as they're kept maintained, androids could theoretically live indefinitely. Though he doesn't know many older androids; all of YoRHa are quite 'young' and he's not sure how old the resistance androids are.

"Do you get to pick how you look, too?" 9S waves a hand, vaguely gesturing at the Carnival in general. "Humans usually look different as they age, don't they?"

Though if Lambert's informal survey and Strange's reaction to a lot of peoples' ages was anything to go by, the Carnival are full of people who don't look the age a human usually would expect. Or something.