21828072 has 64 divisors (see below), whose sum is σ = 63907200. Its totient is φ = 6082560.

The previous prime is 21828071. The next prime is 21828077. The reversal of 21828072 is 27082812.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21828071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5304 + ... + 8472.

It is an arithmetic number, because the mean of its divisors is an integer number (998550).

Almost surely, 2^21828072 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 21828072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31953600).

21828072 is an abundant number, since it is smaller than the sum of its proper divisors (42079128).

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

21828072 is a wasteful number, since it uses less digits than its factorization.

21828072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3226 (or 3222 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 21828072 is about 4672.0522257355. The cubic root of 21828072 is about 279.4721005858.

The spelling of 21828072 in words is "twenty-one million, eight hundred twenty-eight thousand, seventy-two".