204005621 has 4 divisors (see below), whose sum is σ = 204432000. Its totient is φ = 203579244.

The previous prime is 204005609. The next prime is 204005629. The reversal of 204005621 is 126500402.

It is a happy number.

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 204005621 - 2²⁶ = 136896757 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 204005593 and 204005602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204005629) 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 in 3 ways as a sum of consecutive naturals, for example, 212471 + ... + 213428.

It is an arithmetic number, because the mean of its divisors is an integer number (51108000).

Almost surely, 2^204005621 is an apocalyptic number.

It is an amenable number.

204005621 is a deficient number, since it is larger than the sum of its proper divisors (426379).

204005621 is an equidigital number, since it uses as much as digits as its factorization.

204005621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426378.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 204005621 is about 14283.0536300891. The cubic root of 204005621 is about 588.6819384210.

The spelling of 204005621 in words is "two hundred four million, five thousand, six hundred twenty-one".