21582432 has 72 divisors (see below), whose sum is σ = 61936056. Its totient is φ = 7128576.

The previous prime is 21582371. The next prime is 21582439. The reversal of 21582432 is 23428512.

It is a tau number, because it is divible by the number of its divisors (72).

It is a junction number, because it is equal to n+sod(n) for n = 21582396 and 21582405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21582439) 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, 39183 + ... + 39729.

It is an arithmetic number, because the mean of its divisors is an integer number (860223).

Almost surely, 2^21582432 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 21582432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30968028).

21582432 is an abundant number, since it is smaller than the sum of its proper divisors (40353624).

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

21582432 is a wasteful number, since it uses less digits than its factorization.

21582432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 700 (or 689 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

The square root of 21582432 is about 4645.6896151164. The cubic root of 21582432 is about 278.4198063594.

The spelling of 21582432 in words is "twenty-one million, five hundred eighty-two thousand, four hundred thirty-two".