21159503872 has 96 divisors (see below), whose sum is σ = 45845654400. Its totient is φ = 9705406464.

The previous prime is 21159503863. The next prime is 21159503921. The reversal of 21159503872 is 27830595112.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4443829 + ... + 4448587.

It is an arithmetic number, because the mean of its divisors is an integer number (477558900).

Almost surely, 2^21159503872 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 21159503872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22922827200).

21159503872 is an abundant number, since it is smaller than the sum of its proper divisors (24686150528).

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

21159503872 is a wasteful number, since it uses less digits than its factorization.

21159503872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4961 (or 4941 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 43.

The spelling of 21159503872 in words is "twenty-one billion, one hundred fifty-nine million, five hundred three thousand, eight hundred seventy-two".