315

315 = 3² x 5 x 7.

315 = (4 + 3) × (4 + 1) × (4 + 5).

315² = 25³ + 26³ + 27³ + 28³ + 29³ = 99,225.

315 is a divisor of 64² - 1.

315 is a number divisible by each of its digits.

315 is the telephone area code for Syracuse, New York.

Source: What’s Special About This Number?