21536882028 has 36 divisors (see below), whose sum is σ = 54489642480. Its totient is φ = 7172474016.

The previous prime is 21536882023. The next prime is 21536882053. The reversal of 21536882028 is 82028863512.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (21536882023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 229800 + ... + 309647.

It is an arithmetic number, because the mean of its divisors is an integer number (1513601180).

Almost surely, 2^21536882028 is an apocalyptic number.

It is an amenable number.

21536882028 is an abundant number, since it is smaller than the sum of its proper divisors (32952760452).

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

21536882028 is a wasteful number, since it uses less digits than its factorization.

21536882028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 540566 (or 540561 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 21536882028 in words is "twenty-one billion, five hundred thirty-six million, eight hundred eighty-two thousand, twenty-eight".