204666921 has 12 divisors (see below), whose sum is σ = 296117172. Its totient is φ = 136219776.

The previous prime is 204666911. The next prime is 204666983. The reversal of 204666921 is 129666402.

It can be written as a sum of positive squares in 2 ways, for example, as 52490025 + 152176896 = 7245^2 + 12336^2 .

It is not a de Polignac number, because 204666921 - 2¹⁹ = 204142633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (204666911) 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 11 ways as a sum of consecutive naturals, for example, 12876 + ... + 23981.

It is an arithmetic number, because the mean of its divisors is an integer number (24676431).

Almost surely, 2^204666921 is an apocalyptic number.

It is an amenable number.

204666921 is a deficient number, since it is larger than the sum of its proper divisors (91450251).

204666921 is a wasteful number, since it uses less digits than its factorization.

204666921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37480 (or 37477 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 204666921 is about 14306.1847115155. The cubic root of 204666921 is about 589.3173383611.

The spelling of 204666921 in words is "two hundred four million, six hundred sixty-six thousand, nine hundred twenty-one".