204804721 has 9 divisors (see below), whose sum is σ = 225289099. Its totient is φ = 186043000.

The previous prime is 204804713. The next prime is 204804739. The reversal of 204804721 is 127408402.

The square root of 204804721 is 14311.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 314721 + 204490000 = 561^2 + 14300^2 .

It is not a de Polignac number, because 204804721 - 2³ = 204804713 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 204804721.

It is not an unprimeable number, because it can be changed into a prime (204804701) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 156771 + ... + 158071.

Almost surely, 2^204804721 is an apocalyptic number.

204804721 is the 14311-st square number.

204804721 is the 7156-th centered octagonal number.

It is an amenable number.

204804721 is a deficient number, since it is larger than the sum of its proper divisors (20484378).

204804721 is an frugal number, since it uses more digits than its factorization.

204804721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2624 (or 1312 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 28.

The cubic root of 204804721 is about 589.4495689958.

The spelling of 204804721 in words is "two hundred four million, eight hundred four thousand, seven hundred twenty-one".