Natural number
65535 is the integer after 65534 and before 65536.
It is the maximum value of an unsigned 16-bit integer.
In mathematics.
65535 is the sum of 20 through 215 (20 + 21 + 22 + ... + 215) and is therefore a repdigit in base 2 (1111111111111111), in base 4 (33333333), and in base 16 (FFFF).
It is the ninth number formula_1 whose Euler totient has an aliquot sum that is formula_1: formula_3, and the twenty-eighth perfect totient number equal to the sum of its iterated totients.
65535 is the fifteenth 626-gonal number, the fifth 6555-gonal number, and the third 21846-gonal number. 
65535 is the product of the first four Fermat primes: 65535 = (2 + 1)(4 + 1)(16 + 1)(256 + 1). Because of this property, it is possible to construct with compass and straightedge a regular polygon with 65535 sides (see, constructible polygon).
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