204686806705921 has 8 divisors (see below), whose sum is σ = 205055392019624. Its totient is φ = 204318412623360.

The previous prime is 204686806705907. The next prime is 204686806705943. The reversal of 204686806705921 is 129507608686402.

It can be written as a sum of positive squares in 4 ways, for example, as 1056189899521 + 203630616806400 = 1027711^2 + 14269920^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 204686806705921 - 2¹⁷ = 204686806574849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (204686806708921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45665046 + ... + 49946671.

It is an arithmetic number, because the mean of its divisors is an integer number (25631924002453).

Almost surely, 2^{204686806705921} is an apocalyptic number.

It is an amenable number.

204686806705921 is a deficient number, since it is larger than the sum of its proper divisors (368585313703).

204686806705921 is an equidigital number, since it uses as much as digits as its factorization.

204686806705921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95615571.

The product of its (nonzero) digits is 69672960, while the sum is 64.

The spelling of 204686806705921 in words is "two hundred four trillion, six hundred eighty-six billion, eight hundred six million, seven hundred five thousand, nine hundred twenty-one".