How do US write the mobile number?

To write any telephone number in North America (USA, Canada, and 18 island nations and territories in or near the Caribbean) in international format, you write the country code +1, then the area code and phone number, using only spaces to separate groups of numbers (no punctuation at all other than the plus sign).

For example, +1 718 555 0123

The area codes used in Brooklyn, New York, USA, are +1 718, +1 917, +1 347, and +1 929.