204718840621 has 4 divisors (see below), whose sum is σ = 205125836832. Its totient is φ = 204311844412.

The previous prime is 204718840537. The next prime is 204718840679. The reversal of 204718840621 is 126048817402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 204718840621 - 2⁷ = 204718840493 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 (204718840691) 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, 203497351 + ... + 203498356.

It is an arithmetic number, because the mean of its divisors is an integer number (51281459208).

Almost surely, 2^204718840621 is an apocalyptic number.

It is an amenable number.

204718840621 is a deficient number, since it is larger than the sum of its proper divisors (406996211).

204718840621 is an equidigital number, since it uses as much as digits as its factorization.

204718840621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406996210.

The product of its (nonzero) digits is 172032, while the sum is 43.

The spelling of 204718840621 in words is "two hundred four billion, seven hundred eighteen million, eight hundred forty thousand, six hundred twenty-one".