19 is a prime number.
19 has a unique representation as a sum of three squares: 19 = 12 + 32 + 32.
19 is the fourth centered triangular number.
19 is the largest prime number that is a palindrome in Roman numerals (XIX).
19 is the fourth centered triangular number.
19 is the largest prime number that is a palindrome in Roman numerals (XIX).
17 and 19 form a twin prime pair.
Go is played by two players who alternately place black and white pieces on the vacant intersections of a grid of 19 by 19 lines.
Source: Number Gossip
Source: Number Gossip
