204823 has 4 divisors (see below), whose sum is σ = 205920. Its totient is φ = 203728.

The previous prime is 204821. The next prime is 204857. The reversal of 204823 is 328402.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 328402 = 2 ⋅164201.

It is a cyclic number.

It is not a de Polignac number, because 204823 - 2¹ = 204821 is a prime.

It is a super-2 number, since 2×204823² = 83904922658, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

204823 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 204823.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204821) 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, 190 + ... + 667.

It is an arithmetic number, because the mean of its divisors is an integer number (51480).

2²⁰⁴⁸²³ is an apocalyptic number.

204823 is a deficient number, since it is larger than the sum of its proper divisors (1097).

204823 is an equidigital number, since it uses as much as digits as its factorization.

204823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1096.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 204823 is about 452.5737508959. The cubic root of 204823 is about 58.9467104770.

The spelling of 204823 in words is "two hundred four thousand, eight hundred twenty-three".