The number "631" is a three-digit integer that follows 630 and precedes 632. It is an odd number and can be expressed as the sum of the digits 6, 3, and 1, which equals 10. In mathematics, it can be factored into prime numbers as 631 itself, indicating it is a prime number. In the context of area codes, 631 is a telephone area code in the United States, covering parts of Long Island in New York. This area code was established in 1999 and serves regions including Suffolk County and parts of Nassau County.