204651221 has 4 divisors (see below), whose sum is σ = 205621344. Its totient is φ = 203681100.

The previous prime is 204651211. The next prime is 204651241. The reversal of 204651221 is 122156402.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-204651221 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 (204651211) 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, 484745 + ... + 485166.

It is an arithmetic number, because the mean of its divisors is an integer number (51405336).

Almost surely, 2^204651221 is an apocalyptic number.

It is an amenable number.

204651221 is a deficient number, since it is larger than the sum of its proper divisors (970123).

204651221 is an equidigital number, since it uses as much as digits as its factorization.

204651221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 970122.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 204651221 is about 14305.6359872604. The cubic root of 204651221 is about 589.3022691310.

The spelling of 204651221 in words is "two hundred four million, six hundred fifty-one thousand, two hundred twenty-one".