209389 has 8 divisors (see below), whose sum is σ = 225720. Its totient is φ = 193536.

The previous prime is 209381. The next prime is 209393. The reversal of 209389 is 983902.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 20164 + 189225 = 142^2 + 435^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 209389 - 2³ = 209381 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 209389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (209381) 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 7 ways as a sum of consecutive naturals, for example, 1797 + ... + 1909.

It is an arithmetic number, because the mean of its divisors is an integer number (28215).

2²⁰⁹³⁸⁹ is an apocalyptic number.

It is an amenable number.

209389 is a deficient number, since it is larger than the sum of its proper divisors (16331).

209389 is a wasteful number, since it uses less digits than its factorization.

209389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239.

The product of its (nonzero) digits is 3888, while the sum is 31.

The square root of 209389 is about 457.5904282216. The cubic root of 209389 is about 59.3815169209.

It can be divided in two parts, 20 and 9389, that added together give a square (9409 = 97²).

The spelling of 209389 in words is "two hundred nine thousand, three hundred eighty-nine".