204646661 has 2 divisors, whose sum is σ = 204646662. Its totient is φ = 204646660.

The previous prime is 204646573. The next prime is 204646669. The reversal of 204646661 is 166646402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166281025 + 38365636 = 12895^2 + 6194^2 .

It is a cyclic number.

It is not a de Polignac number, because 204646661 - 2²⁶ = 137537797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (204646669) 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 as a sum of consecutive naturals, namely, 102323330 + 102323331.

It is an arithmetic number, because the mean of its divisors is an integer number (102323331).

Almost surely, 2^204646661 is an apocalyptic number.

It is an amenable number.

204646661 is a deficient number, since it is larger than the sum of its proper divisors (1).

204646661 is an equidigital number, since it uses as much as digits as its factorization.

204646661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 35.

The square root of 204646661 is about 14305.4766086279. The cubic root of 204646661 is about 589.2978921910.

The spelling of 204646661 in words is "two hundred four million, six hundred forty-six thousand, six hundred sixty-one".