21204234223 has 4 divisors (see below), whose sum is σ = 21604314168. Its totient is φ = 20804154280.

The previous prime is 21204234209. The next prime is 21204234257. The reversal of 21204234223 is 32243240212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21204234223 - 2¹³ = 21204226031 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 (21204234523) 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, 200039893 + ... + 200039998.

It is an arithmetic number, because the mean of its divisors is an integer number (5401078542).

Almost surely, 2^21204234223 is an apocalyptic number.

21204234223 is a deficient number, since it is larger than the sum of its proper divisors (400079945).

21204234223 is an equidigital number, since it uses as much as digits as its factorization.

21204234223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400079944.

The product of its (nonzero) digits is 4608, while the sum is 25.

Adding to 21204234223 its reverse (32243240212), we get a palindrome (53447474435).

The spelling of 21204234223 in words is "twenty-one billion, two hundred four million, two hundred thirty-four thousand, two hundred twenty-three".