204775221 has 16 divisors (see below), whose sum is σ = 312694784. Its totient is φ = 116768304.

The previous prime is 204775213. The next prime is 204775223. The reversal of 204775221 is 122577402.

It is not a de Polignac number, because 204775221 - 2³ = 204775213 is a prime.

It is a super-2 number, since 2×204775221² = 83865782271197682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204775223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 216 + ... + 20238.

It is an arithmetic number, because the mean of its divisors is an integer number (19543424).

Almost surely, 2^204775221 is an apocalyptic number.

204775221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

204775221 is a deficient number, since it is larger than the sum of its proper divisors (107919563).

204775221 is a wasteful number, since it uses less digits than its factorization.

204775221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20520.

The product of its (nonzero) digits is 7840, while the sum is 30.

The square root of 204775221 is about 14309.9692871788. The cubic root of 204775221 is about 589.4212662673.

The spelling of 204775221 in words is "two hundred four million, seven hundred seventy-five thousand, two hundred twenty-one".