21120004404 has 72 divisors (see below), whose sum is σ = 53824024800. Its totient is φ = 6982471872.

The previous prime is 21120004361. The next prime is 21120004427. The reversal of 21120004404 is 40440002112.

21120004404 is a `hidden beast` number, since 21 + 1 + 200 + 0 + 440 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4218967 + ... + 4223969.

It is an arithmetic number, because the mean of its divisors is an integer number (747555900).

Almost surely, 2^21120004404 is an apocalyptic number.

It is an amenable number.

21120004404 is an abundant number, since it is smaller than the sum of its proper divisors (32704020396).

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

21120004404 is a wasteful number, since it uses less digits than its factorization.

21120004404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5949 (or 5944 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21120004404 its reverse (40440002112), we get a palindrome (61560006516).

The spelling of 21120004404 in words is "twenty-one billion, one hundred twenty million, four thousand, four hundred four".