21123204204 has 24 divisors (see below), whose sum is σ = 50877395968. Its totient is φ = 6813936720.

The previous prime is 21123204187. The next prime is 21123204211. The reversal of 21123204204 is 40240232112.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28391032 + ... + 28391775.

Almost surely, 2^21123204204 is an apocalyptic number.

It is an amenable number.

21123204204 is an abundant number, since it is smaller than the sum of its proper divisors (29754191764).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21123204204 is a wasteful number, since it uses less digits than its factorization.

21123204204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56782845 (or 56782843 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 21123204204 its reverse (40240232112), we get a palindrome (61363436316).

The spelling of 21123204204 in words is "twenty-one billion, one hundred twenty-three million, two hundred four thousand, two hundred four".