209138 has 8 divisors (see below), whose sum is σ = 319788. Its totient is φ = 102544.

The previous prime is 209123. The next prime is 209147. The reversal of 209138 is 831902.

209138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 208849 + 289 = 457^2 + 17^2 .

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

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 209138.

It is an unprimeable number.

209138 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 881 + ... + 1092.

2²⁰⁹¹³⁸ is an apocalyptic number.

209138 is a deficient number, since it is larger than the sum of its proper divisors (110650).

209138 is a wasteful number, since it uses less digits than its factorization.

209138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2028.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 209138 is about 457.3160832510. The cubic root of 209138 is about 59.3577800479.

The spelling of 209138 in words is "two hundred nine thousand, one hundred thirty-eight".