21238403004 has 216 divisors, whose sum is σ = 69075403488. Its totient is φ = 5449731840.

The previous prime is 21238402987. The next prime is 21238403009. The reversal of 21238403004 is 40030483212.

21238403004 is a `hidden beast` number, since 21 + 238 + 403 + 0 + 0 + 4 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21238403009) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 835969 + ... + 860999.

Almost surely, 2^21238403004 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21238403004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34537701744).

21238403004 is an abundant number, since it is smaller than the sum of its proper divisors (47837000484).

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

21238403004 is a wasteful number, since it uses less digits than its factorization.

21238403004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25105 (or 25093 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

Adding to 21238403004 its reverse (40030483212), we get a palindrome (61268886216).

The spelling of 21238403004 in words is "twenty-one billion, two hundred thirty-eight million, four hundred three thousand, four".