205312605 has 32 divisors (see below), whose sum is σ = 354620160. Its totient is φ = 101122560.

The previous prime is 205312603. The next prime is 205312609. The reversal of 205312605 is 506213502.

It is not a de Polignac number, because 205312605 - 2¹ = 205312603 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205312603) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 256 + ... + 20265.

It is an arithmetic number, because the mean of its divisors is an integer number (11081880).

Almost surely, 2^205312605 is an apocalyptic number.

It is an amenable number.

205312605 is a deficient number, since it is larger than the sum of its proper divisors (149307555).

205312605 is a wasteful number, since it uses less digits than its factorization.

205312605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20581.

The product of its (nonzero) digits is 1800, while the sum is 24.

The square root of 205312605 is about 14328.7335448741. The cubic root of 205312605 is about 589.9364146739.

The spelling of 205312605 in words is "two hundred five million, three hundred twelve thousand, six hundred five".