21204204432 has 80 divisors (see below), whose sum is σ = 55442880000. Its totient is φ = 6982362112.

The previous prime is 21204204403. The next prime is 21204204503. The reversal of 21204204432 is 23440240212.

It is a Harshad number since it is a multiple of its sum of digits (24).

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, 8837569 + ... + 8839967.

It is an arithmetic number, because the mean of its divisors is an integer number (693036000).

Almost surely, 2^21204204432 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 21204204432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27721440000).

21204204432 is an abundant number, since it is smaller than the sum of its proper divisors (34238675568).

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

21204204432 is a wasteful number, since it uses less digits than its factorization.

21204204432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4568 (or 4562 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

Adding to 21204204432 its reverse (23440240212), we get a palindrome (44644444644).

The spelling of 21204204432 in words is "twenty-one billion, two hundred four million, two hundred four thousand, four hundred thirty-two".