205897823 has 2 divisors, whose sum is σ = 205897824. Its totient is φ = 205897822.

The previous prime is 205897819. The next prime is 205897831. The reversal of 205897823 is 328798502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205897823 - 2² = 205897819 is a prime.

It is a super-2 number, since 2×205897823² = 84787827032278658, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205897723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102948911 + 102948912.

It is an arithmetic number, because the mean of its divisors is an integer number (102948912).

Almost surely, 2^205897823 is an apocalyptic number.

205897823 is a deficient number, since it is larger than the sum of its proper divisors (1).

205897823 is an equidigital number, since it uses as much as digits as its factorization.

205897823 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 241920, while the sum is 44.

The square root of 205897823 is about 14349.1401484549. The cubic root of 205897823 is about 590.4963963738.

The spelling of 205897823 in words is "two hundred five million, eight hundred ninety-seven thousand, eight hundred twenty-three".