204858661 has 6 divisors (see below), whose sum is σ = 238305030. Its totient is φ = 175593096.

The previous prime is 204858629. The next prime is 204858701. The reversal of 204858661 is 166858402.

204858661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 204318436 + 540225 = 14294^2 + 735^2 .

It is not a de Polignac number, because 204858661 - 2⁵ = 204858629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204858601) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2090346 + ... + 2090443.

It is an arithmetic number, because the mean of its divisors is an integer number (39717505).

Almost surely, 2^204858661 is an apocalyptic number.

It is an amenable number.

204858661 is a deficient number, since it is larger than the sum of its proper divisors (33446369).

204858661 is an equidigital number, since it uses as much as digits as its factorization.

204858661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4180803 (or 4180796 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 40.

The square root of 204858661 is about 14312.8844402517. The cubic root of 204858661 is about 589.5013127881.

The spelling of 204858661 in words is "two hundred four million, eight hundred fifty-eight thousand, six hundred sixty-one".