204204221 has 36 divisors (see below), whose sum is σ = 243376092. Its totient is φ = 171085824.

The previous prime is 204204211. The next prime is 204204227. The reversal of 204204221 is 122402402.

It is a happy number.

It can be written as a sum of positive squares in 18 ways, for example, as 140683321 + 63520900 = 11861^2 + 7970^2 .

It is not a de Polignac number, because 204204221 - 2⁶ = 204204157 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 204204221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204204227) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1807061 + ... + 1807173.

It is an arithmetic number, because the mean of its divisors is an integer number (6760447).

Almost surely, 2^204204221 is an apocalyptic number.

It is an amenable number.

204204221 is a deficient number, since it is larger than the sum of its proper divisors (39171871).

204204221 is a wasteful number, since it uses less digits than its factorization.

204204221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 17.

The square root of 204204221 is about 14290.0042337293. The cubic root of 204204221 is about 588.8729042627.

Adding to 204204221 its reverse (122402402), we get a palindrome (326606623).

The spelling of 204204221 in words is "two hundred four million, two hundred four thousand, two hundred twenty-one".