28305288 has 180 divisors, whose sum is σ = 91971495. Its totient is φ = 8125920.

The previous prime is 28305227. The next prime is 28305313. The reversal of 28305288 is 88250382.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in only one way, i.e., 14152644 + 14152644 = 3762^2 + 3762^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3762.

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

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 1489743 + ... + 1489761.

Almost surely, 2^28305288 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 28305288

28305288 is an abundant number, since it is smaller than the sum of its proper divisors (63666207).

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

28305288 is a wasteful number, since it uses less digits than its factorization.

28305288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78 (or 35 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The square root of 28305288 is about 5320.2714216476. The cubic root of 28305288 is about 304.7585224730.

It can be divided in two parts, 2830 and 5288, that added together give a palindrome (8118).

The spelling of 28305288 in words is "twenty-eight million, three hundred five thousand, two hundred eighty-eight".