209889 has 6 divisors (see below), whose sum is σ = 303186. Its totient is φ = 139920.

The previous prime is 209887. The next prime is 209917. The reversal of 209889 is 988902.

It can be written as a sum of positive squares in only one way, i.e., 176400 + 33489 = 420^2 + 183^2 .

It is not a de Polignac number, because 209889 - 2¹ = 209887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (209887) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11652 + ... + 11669.

It is an arithmetic number, because the mean of its divisors is an integer number (50531).

2²⁰⁹⁸⁸⁹ is an apocalyptic number.

It is an amenable number.

209889 is a deficient number, since it is larger than the sum of its proper divisors (93297).

209889 is a wasteful number, since it uses less digits than its factorization.

209889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23327 (or 23324 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 209889 is about 458.1364425583. The cubic root of 209889 is about 59.4287450575.

It can be divided in two parts, 2098 and 89, that added together give a 7-th power (2187 = 3⁷).

The spelling of 209889 in words is "two hundred nine thousand, eight hundred eighty-nine".