21120400204 has 12 divisors (see below), whose sum is σ = 36991846584. Its totient is φ = 10551301184.

The previous prime is 21120400193. The next prime is 21120400207. The reversal of 21120400204 is 40200402112.

It is not an unprimeable number, because it can be changed into a prime (21120400207) 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, 2219389 + ... + 2228884.

It is an arithmetic number, because the mean of its divisors is an integer number (3082653882).

Almost surely, 2^21120400204 is an apocalyptic number.

It is an amenable number.

21120400204 is a deficient number, since it is larger than the sum of its proper divisors (15871446380).

21120400204 is a wasteful number, since it uses less digits than its factorization.

21120400204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4449464 (or 4449462 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21120400204 its reverse (40200402112), we get a palindrome (61320802316).

The spelling of 21120400204 in words is "twenty-one billion, one hundred twenty million, four hundred thousand, two hundred four".