630 is a triangular number. It is the sum of the first 35 integers: 1 + 2 + 3 + . . . + 34 + 35 = 630. 630 is also three times a triangular number (210) and six times a triangular number (105).
630 is 21312 in base 4.
630 is the sum of six consecutive primes: 97 + 101 + 103 + 107 + 109 + 113 = 630.
630 is the height and the span (in feet) of the stainless steel arch “Gateway to the West” in St. Louis, Missouri.
Source: What’s Special About This Number?
