205381 has 4 divisors (see below), whose sum is σ = 224064. Its totient is φ = 186700.

The previous prime is 205357. The next prime is 205391. The reversal of 205381 is 183502.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 205381 - 2⁷ = 205253 is a prime.

It is a super-2 number, since 2×205381² = 84362710322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205391) 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, 9325 + ... + 9346.

It is an arithmetic number, because the mean of its divisors is an integer number (56016).

205381 is a Friedman number, since it can be written as 2+(58+1+0)^3, using all its digits and the basic arithmetic operations.

2²⁰⁵³⁸¹ is an apocalyptic number.

It is an amenable number.

205381 is a deficient number, since it is larger than the sum of its proper divisors (18683).

205381 is a wasteful number, since it uses less digits than its factorization.

205381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18682.

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

The square root of 205381 is about 453.1898057106. The cubic root of 205381 is about 59.0001915152. Note that the first 3 decimals are identical.

Adding to 205381 its reverse (183502), we get a palindrome (388883).

The spelling of 205381 in words is "two hundred five thousand, three hundred eighty-one".