28388305 has 8 divisors (see below), whose sum is σ = 37162944. Its totient is φ = 20646000.

The previous prime is 28388267. The next prime is 28388323. The reversal of 28388305 is 50388382.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28388305 - 2¹³ = 28380113 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 258021 + ... + 258130.

It is an arithmetic number, because the mean of its divisors is an integer number (4645368).

Almost surely, 2^28388305 is an apocalyptic number.

It is an amenable number.

28388305 is a deficient number, since it is larger than the sum of its proper divisors (8774639).

28388305 is a wasteful number, since it uses less digits than its factorization.

28388305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516167.

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 28388305 is about 5328.0676609818. The cubic root of 28388305 is about 305.0561752661.

It can be divided in two parts, 283 and 88305, that added together give a palindrome (88588).

The spelling of 28388305 in words is "twenty-eight million, three hundred eighty-eight thousand, three hundred five".