Like every positive integer, the number 19 possesses some fascinating properties. For example, 19 is the smallest prime that is equal to the product of its digits plus the sum of its digits; 19 = 4! − 3! + 2! − 1!; 19 times its reversal (91) is the famous Hardy-Ramanujan number 1729; the sum of 19 consecutive Fibonacci numbers starting from the 19 Fibonacci number is prime; 19 is the smallest p...