21154728804 has 96 divisors (see below), whose sum is σ = 57057146496. Its totient is φ = 6029076480.

The previous prime is 21154728797. The next prime is 21154728827. The reversal of 21154728804 is 40882745112.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4335214 + ... + 4340090.

It is an arithmetic number, because the mean of its divisors is an integer number (594345276).

Almost surely, 2^21154728804 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 21154728804, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28528573248).

21154728804 is an abundant number, since it is smaller than the sum of its proper divisors (35902417692).

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

21154728804 is a wasteful number, since it uses less digits than its factorization.

21154728804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6845 (or 6843 counting only the distinct ones).

The product of its (nonzero) digits is 143360, while the sum is 42.

The spelling of 21154728804 in words is "twenty-one billion, one hundred fifty-four million, seven hundred twenty-eight thousand, eight hundred four".