204204310021 has 4 divisors (see below), whose sum is σ = 205058721600. Its totient is φ = 203349898444.

The previous prime is 204204310019. The next prime is 204204310039. The reversal of 204204310021 is 120013402402.

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 204204310021 - 2¹ = 204204310019 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 (204204310421) 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, 427205431 + ... + 427205908.

It is an arithmetic number, because the mean of its divisors is an integer number (51264680400).

Almost surely, 2^204204310021 is an apocalyptic number.

It is an amenable number.

204204310021 is a deficient number, since it is larger than the sum of its proper divisors (854411579).

204204310021 is an equidigital number, since it uses as much as digits as its factorization.

204204310021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 854411578.

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 204204310021 its reverse (120013402402), we get a palindrome (324217712423).

The spelling of 204204310021 in words is "two hundred four billion, two hundred four million, three hundred ten thousand, twenty-one".