21726432 has 144 divisors (see below), whose sum is σ = 76134240. Its totient is φ = 5723136.

The previous prime is 21726427. The next prime is 21726461. The reversal of 21726432 is 23462712.

21726432 is a `hidden beast` number, since 2 + 17 + 2 + 643 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21726396 and 21726405.

It is a congruent number.

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, 25794 + ... + 26622.

It is an arithmetic number, because the mean of its divisors is an integer number (528710).

Almost surely, 2^21726432 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 21726432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38067120).

21726432 is an abundant number, since it is smaller than the sum of its proper divisors (54407808).

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

21726432 is a wasteful number, since it uses less digits than its factorization.

21726432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 865 (or 854 counting only the distinct ones).

The product of its digits is 4032, while the sum is 27.

The square root of 21726432 is about 4661.1620868620. The cubic root of 21726432 is about 279.0376485981.

The spelling of 21726432 in words is "twenty-one million, seven hundred twenty-six thousand, four hundred thirty-two".