204566661 has 32 divisors (see below), whose sum is σ = 345582720. Its totient is φ = 118478592.

The previous prime is 204566657. The next prime is 204566723. The reversal of 204566661 is 166665402.

It is a happy number.

It is not a de Polignac number, because 204566661 - 2² = 204566657 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204566641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11175 + ... + 23108.

It is an arithmetic number, because the mean of its divisors is an integer number (10799460).

Almost surely, 2^204566661 is an apocalyptic number.

It is an amenable number.

204566661 is a deficient number, since it is larger than the sum of its proper divisors (141016059).

204566661 is a wasteful number, since it uses less digits than its factorization.

204566661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34322 (or 34316 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 204566661 is about 14302.6802033745. The cubic root of 204566661 is about 589.2210931925.

The spelling of 204566661 in words is "two hundred four million, five hundred sixty-six thousand, six hundred sixty-one".