22009728 has 64 divisors (see below), whose sum is σ = 62974800. Its totient is φ = 6770688.

The previous prime is 22009723. The next prime is 22009739. The reversal of 22009728 is 82790022.

It is a tau number, because it is divible by the number of its divisors (64).

It is a junction number, because it is equal to n+sod(n) for n = 22009695 and 22009704.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22009723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2788 + ... + 7196.

Almost surely, 2^22009728 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 22009728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31487400).

22009728 is an abundant number, since it is smaller than the sum of its proper divisors (40965072).

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

22009728 is a wasteful number, since it uses less digits than its factorization.

22009728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4439 (or 4427 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 22009728 is about 4691.4526534966. The cubic root of 22009728 is about 280.2452273411.

The spelling of 22009728 in words is "twenty-two million, nine thousand, seven hundred twenty-eight".