205138 has 8 divisors (see below), whose sum is σ = 310860. Its totient is φ = 101520.

The previous prime is 205133. The next prime is 205141. The reversal of 205138 is 831502.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 199809 + 5329 = 447^2 + 73^2 .

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

It is not an unprimeable number, because it can be changed into a prime (205133) 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, 253 + ... + 688.

2²⁰⁵¹³⁸ is an apocalyptic number.

205138 is a deficient number, since it is larger than the sum of its proper divisors (105722).

205138 is a wasteful number, since it uses less digits than its factorization.

205138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1052.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 205138 is about 452.9216267744. The cubic root of 205138 is about 58.9769133077.

It can be divided in two parts, 205 and 138, that added together give a palindrome (343).

The spelling of 205138 in words is "two hundred five thousand, one hundred thirty-eight".