21534538884 has 24 divisors (see below), whose sum is σ = 50294556480. Its totient is φ = 7171422624.

The previous prime is 21534538873. The next prime is 21534538889. The reversal of 21534538884 is 48883543512.

It is not an unprimeable number, because it can be changed into a prime (21534538889) 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, 831339 + ... + 856850.

It is an arithmetic number, because the mean of its divisors is an integer number (2095606520).

Almost surely, 2^21534538884 is an apocalyptic number.

It is an amenable number.

21534538884 is an abundant number, since it is smaller than the sum of its proper divisors (28760017596).

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

21534538884 is a wasteful number, since it uses less digits than its factorization.

21534538884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1689259 (or 1689257 counting only the distinct ones).

The product of its digits is 3686400, while the sum is 51.

The spelling of 21534538884 in words is "twenty-one billion, five hundred thirty-four million, five hundred thirty-eight thousand, eight hundred eighty-four".