205407 has 12 divisors (see below), whose sum is σ = 307320. Its totient is φ = 132048.

The previous prime is 205399. The next prime is 205417. The reversal of 205407 is 704502.

It is a happy number.

It is not a de Polignac number, because 205407 - 2³ = 205399 is a prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 205407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205417) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 133 + ... + 654.

It is an arithmetic number, because the mean of its divisors is an integer number (25610).

2²⁰⁵⁴⁰⁷ is an apocalyptic number.

205407 is a deficient number, since it is larger than the sum of its proper divisors (101913).

205407 is a wasteful number, since it uses less digits than its factorization.

205407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 822 (or 819 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 18.

The square root of 205407 is about 453.2184903554. The cubic root of 205407 is about 59.0026811000.

Adding to 205407 its reverse (704502), we get a palindrome (909909).

The spelling of 205407 in words is "two hundred five thousand, four hundred seven".