22438728 has 128 divisors (see below), whose sum is σ = 68745600. Its totient is φ = 6739200.

The previous prime is 22438727. The next prime is 22438729. The reversal of 22438728 is 82783422.

It is an interprime number because it is at equal distance from previous prime (22438727) and next prime (22438729).

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

It is a junction number, because it is equal to n+sod(n) for n = 22438692 and 22438701.

It is not an unprimeable number, because it can be changed into a prime (22438727) 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 31 ways as a sum of consecutive naturals, for example, 171223 + ... + 171353.

It is an arithmetic number, because the mean of its divisors is an integer number (537075).

Almost surely, 2^22438728 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 22438728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34372800).

22438728 is an abundant number, since it is smaller than the sum of its proper divisors (46306872).

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

22438728 is a wasteful number, since it uses less digits than its factorization.

22438728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220 (or 210 counting only the distinct ones).

The product of its digits is 43008, while the sum is 36.

The square root of 22438728 is about 4736.9534513229. The cubic root of 22438728 is about 282.0543127620.

The spelling of 22438728 in words is "twenty-two million, four hundred thirty-eight thousand, seven hundred twenty-eight".