204640666 has 8 divisors (see below), whose sum is σ = 307628244. Its totient is φ = 102097920.

The previous prime is 204640613. The next prime is 204640669. The reversal of 204640666 is 666046402.

It can be written as a sum of positive squares in 2 ways, for example, as 170172025 + 34468641 = 13045^2 + 5871^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (204640669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110055 + ... + 111898.

Almost surely, 2^204640666 is an apocalyptic number.

204640666 is a deficient number, since it is larger than the sum of its proper divisors (102987578).

204640666 is a wasteful number, since it uses less digits than its factorization.

204640666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222416.

The product of its (nonzero) digits is 41472, while the sum is 34.

The square root of 204640666 is about 14305.2670719564. The cubic root of 204640666 is about 589.2921377599.

The spelling of 204640666 in words is "two hundred four million, six hundred forty thousand, six hundred sixty-six".