208809 has 6 divisors (see below), whose sum is σ = 301626. Its totient is φ = 139200.

The previous prime is 208807. The next prime is 208837. The reversal of 208809 is 908802.

It can be written as a sum of positive squares in only one way, i.e., 205209 + 3600 = 453^2 + 60^2 .

It is not a de Polignac number, because 208809 - 2¹ = 208807 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 208809.

It is not an unprimeable number, because it can be changed into a prime (208807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11592 + ... + 11609.

It is an arithmetic number, because the mean of its divisors is an integer number (50271).

2²⁰⁸⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

208809 is a deficient number, since it is larger than the sum of its proper divisors (92817).

208809 is a wasteful number, since it uses less digits than its factorization.

208809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23207 (or 23204 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 208809 is about 456.9562342282. The cubic root of 208809 is about 59.3266379966.

The spelling of 208809 in words is "two hundred eight thousand, eight hundred nine".