21440832 has 168 divisors, whose sum is σ = 68799456. Its totient is φ = 5870592.

The previous prime is 21440821. The next prime is 21440833. The reversal of 21440832 is 23804412.

It is a tau number, because it is divible by the number of its divisors (168).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21440833) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 404518 + ... + 404570.

Almost surely, 2^21440832 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 21440832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34399728).

21440832 is an abundant number, since it is smaller than the sum of its proper divisors (47358624).

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

21440832 is a wasteful number, since it uses less digits than its factorization.

21440832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 21440832 is about 4630.4246025608. The cubic root of 21440832 is about 277.8095757850.

The spelling of 21440832 in words is "twenty-one million, four hundred forty thousand, eight hundred thirty-two".