28303505 has 8 divisors (see below), whose sum is σ = 34021824. Its totient is φ = 22604400.

The previous prime is 28303493. The next prime is 28303523. The reversal of 28303505 is 50530382.

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

It is not a de Polignac number, because 28303505 - 2⁶ = 28303441 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, 1331 + ... + 7640.

It is an arithmetic number, because the mean of its divisors is an integer number (4252728).

Almost surely, 2^28303505 is an apocalyptic number.

It is an amenable number.

28303505 is a deficient number, since it is larger than the sum of its proper divisors (5718319).

28303505 is an equidigital number, since it uses as much as digits as its factorization.

28303505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9607.

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 28303505 is about 5320.1038523698. The cubic root of 28303505 is about 304.7521232464.

Adding to 28303505 its reverse (50530382), we get a palindrome (78833887).

The spelling of 28303505 in words is "twenty-eight million, three hundred three thousand, five hundred five".