204212221 has 4 divisors (see below), whose sum is σ = 210799744. Its totient is φ = 197624700.

The previous prime is 204212207. The next prime is 204212231. The reversal of 204212221 is 122212402.

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 204212221 - 2⁷ = 204212093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 204212195 and 204212204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204212231) 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, 3293715 + ... + 3293776.

It is an arithmetic number, because the mean of its divisors is an integer number (52699936).

Almost surely, 2^204212221 is an apocalyptic number.

It is an amenable number.

204212221 is a deficient number, since it is larger than the sum of its proper divisors (6587523).

204212221 is an equidigital number, since it uses as much as digits as its factorization.

204212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6587522.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 204212221 is about 14290.2841469300. The cubic root of 204212221 is about 588.8805941490.

Adding to 204212221 its reverse (122212402), we get a palindrome (326424623).

The spelling of 204212221 in words is "two hundred four million, two hundred twelve thousand, two hundred twenty-one".