Mersenne prime Mersenne prime In mathematics, a Mersenne prime is a prime number that is one less than a power of two. That is, it is a prime number of the form for some integer . They are named after Marin Mersenne, a French Minim friar, who studied them in the early 17th century. The exponents which give Mersenne primes are 2, 3, 5, 7, 13, 17, 19, 31, ... and the resulting Mersenne primes are 3, 7, 31, 127, 8191, 131071, 524287, 2147483647, ... . If is a composite number then so is . ( is divisible by both and .)
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