Their help page technically says you can use the same phone number on up to 10 accounts, but that hasn't been the case in 4–5 years or more. It's more like 2–4 accounts per number allowed in my experience, and there is a few week cooldown on reusing a number even if you've already removed it from all accounts.
I don't think you can use the same email on multiple accounts at the same time, but using address extensions or creating new emails is easy.
I don't think you can use the same email on multiple accounts at the same time, but using address extensions or creating new emails is easy.