21354432 has 56 divisors (see below), whose sum is σ = 61642752. Its totient is φ = 6470400.

The previous prime is 21354413. The next prime is 21354433. The reversal of 21354432 is 23445312.

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 (21354433) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2944 + ... + 7167.

Almost surely, 2^21354432 is an apocalyptic number.

21354432 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21354432 is an abundant number, since it is smaller than the sum of its proper divisors (40288320).

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

21354432 is a wasteful number, since it uses less digits than its factorization.

21354432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10137 (or 10127 counting only the distinct ones).

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

The square root of 21354432 is about 4621.0855867426. The cubic root of 21354432 is about 277.4359108550.

Adding to 21354432 its reverse (23445312), we get a palindrome (44799744).

It can be divided in two parts, 213 and 54432, that added together give a palindrome (54645).

The spelling of 21354432 in words is "twenty-one million, three hundred fifty-four thousand, four hundred thirty-two".