21533832 has 96 divisors (see below), whose sum is σ = 62857080. Its totient is φ = 6635520.

The previous prime is 21533807. The next prime is 21533843. The reversal of 21533832 is 23833512.

It can be written as a sum of positive squares in 4 ways, for example, as 21399876 + 133956 = 4626^2 + 366^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21533796 and 21533805.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 89232 + ... + 89472.

Almost surely, 2^21533832 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 21533832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31428540).

21533832 is an abundant number, since it is smaller than the sum of its proper divisors (41323248).

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

21533832 is a wasteful number, since it uses less digits than its factorization.

21533832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343 (or 336 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 21533832 is about 4640.4560120747. The cubic root of 21533832 is about 278.2106644676.

The spelling of 21533832 in words is "twenty-one million, five hundred thirty-three thousand, eight hundred thirty-two".