204231021 has 16 divisors (see below), whose sum is σ = 282172800. Its totient is φ = 131237568.

The previous prime is 204231017. The next prime is 204231023. The reversal of 204231021 is 120132402.

It is not a de Polignac number, because 204231021 - 2² = 204231017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204231023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61635 + ... + 64863.

It is an arithmetic number, because the mean of its divisors is an integer number (17635800).

Almost surely, 2^204231021 is an apocalyptic number.

It is an amenable number.

204231021 is a deficient number, since it is larger than the sum of its proper divisors (77941779).

204231021 is a wasteful number, since it uses less digits than its factorization.

204231021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3988.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 204231021 is about 14290.9419213710. The cubic root of 204231021 is about 588.8986645912.

Adding to 204231021 its reverse (120132402), we get a palindrome (324363423).

The spelling of 204231021 in words is "two hundred four million, two hundred thirty-one thousand, twenty-one".