21456832 has 28 divisors (see below), whose sum is σ = 43068240. Its totient is φ = 10605056.

The previous prime is 21456829. The next prime is 21456859. The reversal of 21456832 is 23865412.

It is a junction number, because it is equal to n+sod(n) for n = 21456794 and 21456803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3813 + ... + 7579.

Almost surely, 2^21456832 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 21456832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21534120).

21456832 is an abundant number, since it is smaller than the sum of its proper divisors (21611408).

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

21456832 is an equidigital number, since it uses as much as digits as its factorization.

21456832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3868 (or 3858 counting only the distinct ones).

The product of its digits is 11520, while the sum is 31.

The square root of 21456832 is about 4632.1519836897. The cubic root of 21456832 is about 277.8786627807.

The spelling of 21456832 in words is "twenty-one million, four hundred fifty-six thousand, eight hundred thirty-two".