2204400021 has 4 divisors (see below), whose sum is σ = 2939200032. Its totient is φ = 1469600012.

The previous prime is 2204400001. The next prime is 2204400091. The reversal of 2204400021 is 1200044022.

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 2204400021 - 2⁶ = 2204399957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2204400001) 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, 367400001 + ... + 367400006.

It is an arithmetic number, because the mean of its divisors is an integer number (734800008).

Almost surely, 2^2204400021 is an apocalyptic number.

It is an amenable number.

2204400021 is a deficient number, since it is larger than the sum of its proper divisors (734800011).

2204400021 is an equidigital number, since it uses as much as digits as its factorization.

2204400021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 734800010.

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 2204400021 is about 46951.0385508138. The cubic root of 2204400021 is about 1301.4579345495.

Adding to 2204400021 its reverse (1200044022), we get a palindrome (3404444043).

The spelling of 2204400021 in words is "two billion, two hundred four million, four hundred thousand, twenty-one".