21120404404 has 48 divisors (see below), whose sum is σ = 41043562560. Its totient is φ = 9428405760.

The previous prime is 21120404387. The next prime is 21120404411. The reversal of 21120404404 is 40440402112.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3207964 + ... + 3214540.

It is an arithmetic number, because the mean of its divisors is an integer number (855074220).

Almost surely, 2^21120404404 is an apocalyptic number.

It is an amenable number.

21120404404 is a deficient number, since it is larger than the sum of its proper divisors (19923158156).

21120404404 is a wasteful number, since it uses less digits than its factorization.

21120404404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7888 (or 7886 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 22.

Adding to 21120404404 its reverse (40440402112), we get a palindrome (61560806516).

It can be divided in two parts, 21120 and 404404, that added together give a palindrome (425524).

The spelling of 21120404404 in words is "twenty-one billion, one hundred twenty million, four hundred four thousand, four hundred four".