Fortunate number Fortunate number A Fortunate number, named after Reo Fortune, is the smallest integer "m" > 1 such that, for a given positive integer "n", "p"# + "m" is a prime number, where the primorial "p"# is the product of the first "n" prime numbers. For example, to find the seventh Fortunate number, one would first calculate the product of the first seven primes (2, 3, 5, 7, 11, 13 and 17), which is 510510. Adding 2 to that gives another even number, while adding 3 would give another multiple of 3. One would similarly rule out the integers up to
17 (number) the only prime number which is the sum of four consecutive primes (2,3,5,7). Any other four consecutive primes summed would always produce an even number, thereby divisible by 2 and so not prime. In Catalan, 17 is the first compound number ("disset"). The numbers 11 ("onze") through 16 ("setze") have their own names. In French, 17 is the first compound number ("dix-sept"). The numbers 11 ("onze") through 16 ("seize") have their own names. In Italian, 17 is also the first compound number ("diciassette"), whereas sixteen is "sedici". Seventeen is: 17 (number) 17 (seventeen) is the natural number following 16 and