204220421 has 4 divisors (see below), whose sum is σ = 206680992. Its totient is φ = 201759852.

The previous prime is 204220411. The next prime is 204220463. The reversal of 204220421 is 124022402.

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-204220421 is a prime.

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 204220421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204220411) 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, 1230161 + ... + 1230326.

It is an arithmetic number, because the mean of its divisors is an integer number (51670248).

Almost surely, 2^204220421 is an apocalyptic number.

It is an amenable number.

204220421 is a deficient number, since it is larger than the sum of its proper divisors (2460571).

204220421 is an equidigital number, since it uses as much as digits as its factorization.

204220421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2460570.

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

The square root of 204220421 is about 14290.5710522708. The cubic root of 204220421 is about 588.8884760740. Note that the first 3 decimals are identical.

Adding to 204220421 its reverse (124022402), we get a palindrome (328242823).

The spelling of 204220421 in words is "two hundred four million, two hundred twenty thousand, four hundred twenty-one".