11 (number) "ùndici" (but in Spanish and Portuguese, 16, and in French, 17 is the first compound number), Chinese 十一 "shí yī", Korean 열한 "yeol han". 11 is a prime number. It is the smallest two-digit prime number in the decimal base. The next prime is 13, with which it comprises a twin prime. If a number is divisible by 11, reversing its digits will result in another multiple of 11. As long as no two adjacent digits of a number added together exceed 9, then multiplying the number by 11, reversing the digits of the product, and dividing that new number
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