204123 has 4 divisors (see below), whose sum is σ = 272168. Its totient is φ = 136080.

The previous prime is 204107. The next prime is 204133. The reversal of 204123 is 321402.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 204123 - 2⁴ = 204107 is a prime.

It is a D-number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 204099 and 204108.

It is not an unprimeable number, because it can be changed into a prime (204133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34018 + ... + 34023.

It is an arithmetic number, because the mean of its divisors is an integer number (68042).

2²⁰⁴¹²³ is an apocalyptic number.

204123 is a deficient number, since it is larger than the sum of its proper divisors (68045).

204123 is an equidigital number, since it uses as much as digits as its factorization.

204123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68044.

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 204123 is about 451.7997343957. The cubic root of 204123 is about 58.8794820358.

Adding to 204123 its reverse (321402), we get a palindrome (525525).

The spelling of 204123 in words is "two hundred four thousand, one hundred twenty-three", and thus it is an iban number.