205697 has 8 divisors (see below), whose sum is σ = 219240. Its totient is φ = 192640.

The previous prime is 205663. The next prime is 205703. The reversal of 205697 is 796502.

It can be written as a sum of positive squares in 4 ways, for example, as 25921 + 179776 = 161^2 + 424^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 205697 - 2⁶ = 205633 is a prime.

It is a super-2 number, since 2×205697² = 84622511618, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 205697.

It is not an unprimeable number, because it can be changed into a prime (205607) 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 7 ways as a sum of consecutive naturals, for example, 1103 + ... + 1275.

It is an arithmetic number, because the mean of its divisors is an integer number (27405).

2²⁰⁵⁶⁹⁷ is an apocalyptic number.

It is an amenable number.

205697 is a deficient number, since it is larger than the sum of its proper divisors (13543).

205697 is a wasteful number, since it uses less digits than its factorization.

205697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243.

The product of its (nonzero) digits is 3780, while the sum is 29.

The square root of 205697 is about 453.5383115019. The cubic root of 205697 is about 59.0304353170.

The spelling of 205697 in words is "two hundred five thousand, six hundred ninety-seven".