7
7
7 is the natural number following and preceding . Seven, the fourth prime number, is not only a Mersenne prime but also a double Mersenne prime since the exponent, 3, is itself a Mersenne prime. It is also a Newman–Shanks–Williams prime, a Woodall prime, a factorial prime, a lucky prime, a happy number, a safe prime and the fourth Heegner number, Seven is the lowest natural number that cannot be represented as the sum of the squares of three integers., Seven is the aliquot sum of one number, the cubic number and is the base of the 7-aliquot tree, n = 7 is the first natural number for which the next statement does not hold: "Two nilpotent ...The above text is a snippet from Wikipedia: 7 (number)
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