288809 has 4 divisors (see below), whose sum is σ = 290004. Its totient is φ = 287616.

The previous prime is 288803. The next prime is 288817. The reversal of 288809 is 908882.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 183184 + 105625 = 428^2 + 325^2 .

It is a cyclic number.

It is not a de Polignac number, because 288809 - 2¹⁶ = 223273 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 288809.

It is not an unprimeable number, because it can be changed into a prime (288803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 92 + ... + 765.

It is an arithmetic number, because the mean of its divisors is an integer number (72501).

2²⁸⁸⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

288809 is a deficient number, since it is larger than the sum of its proper divisors (1195).

288809 is an equidigital number, since it uses as much as digits as its factorization.

288809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1194.

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 288809 is about 537.4095272695. The cubic root of 288809 is about 66.1003218720.

The spelling of 288809 in words is "two hundred eighty-eight thousand, eight hundred nine".