204213409 has 4 divisors (see below), whose sum is σ = 205466416. Its totient is φ = 202960404.

The previous prime is 204213391. The next prime is 204213413. The reversal of 204213409 is 904312402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 204213409 - 2⁷ = 204213281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (204213479) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 626259 + ... + 626584.

It is an arithmetic number, because the mean of its divisors is an integer number (51366604).

Almost surely, 2^204213409 is an apocalyptic number.

It is an amenable number.

204213409 is a deficient number, since it is larger than the sum of its proper divisors (1253007).

204213409 is a wasteful number, since it uses less digits than its factorization.

204213409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1253006.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 204213409 is about 14290.3257135728. The cubic root of 204213409 is about 588.8817360799.

It can be divided in two parts, 2042 and 13409, that added together give a palindrome (15451).

The spelling of 204213409 in words is "two hundred four million, two hundred thirteen thousand, four hundred nine".