21204124404 has 12 divisors (see below), whose sum is σ = 49476290304. Its totient is φ = 7068041464.

The previous prime is 21204124397. The next prime is 21204124427. The reversal of 21204124404 is 40442140212.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21204124404² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 883505172 + ... + 883505195.

It is an arithmetic number, because the mean of its divisors is an integer number (4123024192).

Almost surely, 2^21204124404 is an apocalyptic number.

It is an amenable number.

21204124404 is an abundant number, since it is smaller than the sum of its proper divisors (28272165900).

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

21204124404 is a wasteful number, since it uses less digits than its factorization.

21204124404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1767010374 (or 1767010372 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 24.

Adding to 21204124404 its reverse (40442140212), we get a palindrome (61646264616).

The spelling of 21204124404 in words is "twenty-one billion, two hundred four million, one hundred twenty-four thousand, four hundred four".