300 (number) nontotient. 315 = 3 × 5 × 7. 315 is a Harshad number 316 = 2 × 79. 316 is a centered triangular number and a centered heptagonal number 317 is a prime number, Eisenstein prime with no imaginary part, Chen prime, and a strictly non-palindromic number. 317 is also shorthand for the LM317 adjustable regulator chip. It is also the area code for the Indianapolis region. 318 = 2 × 3 × 53. It is a sphenic number, nontotient, and the sum of twelve consecutive primes (7 + 11 + 13 + 17 + 19 + 23 + 29
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