28388844 has 72 divisors (see below), whose sum is σ = 82909008. Its totient is φ = 8094720.

The previous prime is 28388819. The next prime is 28388849. The reversal of 28388844 is 44888382.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 28388844.

It is not an unprimeable number, because it can be changed into a prime (28388849) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4624 + ... + 8840.

It is an arithmetic number, because the mean of its divisors is an integer number (1151514).

Almost surely, 2^28388844 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 28388844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41454504).

28388844 is an abundant number, since it is smaller than the sum of its proper divisors (54520164).

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

28388844 is a wasteful number, since it uses less digits than its factorization.

28388844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4255 (or 4250 counting only the distinct ones).

The product of its digits is 393216, while the sum is 45.

The square root of 28388844 is about 5328.1182419312. The cubic root of 28388844 is about 305.0581059231.

The spelling of 28388844 in words is "twenty-eight million, three hundred eighty-eight thousand, eight hundred forty-four".