21534432 has 24 divisors (see below), whose sum is σ = 56528136. Its totient is φ = 7178112.

The previous prime is 21534421. The next prime is 21534437. The reversal of 21534432 is 23443512.

It is a tau number, because it is divible by the number of its divisors (24).

It is a hoax number, since the sum of its digits (24) coincides with the sum of the digits of its distinct prime factors.

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 (21534437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112063 + ... + 112254.

It is an arithmetic number, because the mean of its divisors is an integer number (2355339).

Almost surely, 2^21534432 is an apocalyptic number.

It is an amenable number.

21534432 is an abundant number, since it is smaller than the sum of its proper divisors (34993704).

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

21534432 is a wasteful number, since it uses less digits than its factorization.

21534432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224330 (or 224322 counting only the distinct ones).

The product of its digits is 2880, while the sum is 24.

The square root of 21534432 is about 4640.5206604432. The cubic root of 21534432 is about 278.2132483837.

Adding to 21534432 its reverse (23443512), we get a palindrome (44977944).

The spelling of 21534432 in words is "twenty-one million, five hundred thirty-four thousand, four hundred thirty-two".