28688544 has 144 divisors (see below), whose sum is σ = 87744384. Its totient is φ = 8870400.

The previous prime is 28688533. The next prime is 28688557. The reversal of 28688544 is 44588682.

28688544 is a `hidden beast` number, since 28 + 6 + 88 + 544 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

Its product of digits (491520) is a multiple of the sum of its prime divisors (160).

It is a self number, because there is not a number n which added to its sum of digits gives 28688544.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 404029 + ... + 404099.

It is an arithmetic number, because the mean of its divisors is an integer number (609336).

Almost surely, 2^28688544 is an apocalyptic number.

28688544 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28688544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43872192).

28688544 is an abundant number, since it is smaller than the sum of its proper divisors (59055840).

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

28688544 is a wasteful number, since it uses less digits than its factorization.

28688544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 160 counting only the distinct ones).

The product of its digits is 491520, while the sum is 45.

The square root of 28688544 is about 5356.1687800143. The cubic root of 28688544 is about 306.1278461046.

The spelling of 28688544 in words is "twenty-eight million, six hundred eighty-eight thousand, five hundred forty-four".