21004204404 has 24 divisors (see below), whose sum is σ = 49023476320. Its totient is φ = 6999449184.

The previous prime is 21004204399. The next prime is 21004204409. The reversal of 21004204404 is 40440240012.

It is an interprime number because it is at equal distance from previous prime (21004204399) and next prime (21004204409).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21004204409) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 198874 + ... + 285585.

Almost surely, 2^21004204404 is an apocalyptic number.

It is an amenable number.

21004204404 is an abundant number, since it is smaller than the sum of its proper divisors (28019271916).

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

21004204404 is a wasteful number, since it uses less digits than its factorization.

21004204404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488079 (or 488077 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 21.

Adding to 21004204404 its reverse (40440240012), we get a palindrome (61444444416).

The spelling of 21004204404 in words is "twenty-one billion, four million, two hundred four thousand, four hundred four".