What's your phone number? (informal)
What's your phone number? (formal)
My phone number is 0735455577.
Can you give me your email address? (informal)
What's your email address? (formal)
My email address is email@example.com.
Can I call you? (informal)
Can I call you? (formal)
cell phone number
I don't have a cell phone.
I don't have an email address.
Are you on Facebook?
Are you on WhatsApp? (informal)