21824928 has 36 divisors (see below), whose sum is σ = 62065458. Its totient is φ = 7274880.

The previous prime is 21824921. The next prime is 21824941. The reversal of 21824928 is 82942812.

It can be written as a sum of positive squares in only one way, i.e., 20684304 + 1140624 = 4548^2 + 1068^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

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 = 21824892 and 21824901.

It is not an unprimeable number, because it can be changed into a prime (21824921) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 37603 + ... + 38178.

Almost surely, 2^21824928 is an apocalyptic number.

It is an amenable number.

21824928 is an abundant number, since it is smaller than the sum of its proper divisors (40240530).

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

21824928 is a wasteful number, since it uses less digits than its factorization.

21824928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75797 (or 75786 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 21824928 is about 4671.7157447773. The cubic root of 21824928 is about 279.4586820473.

The spelling of 21824928 in words is "twenty-one million, eight hundred twenty-four thousand, nine hundred twenty-eight".