28223505 has 16 divisors (see below), whose sum is σ = 50175360. Its totient is φ = 15052464.

The previous prime is 28223477. The next prime is 28223509. The reversal of 28223505 is 50532282.

It is not a de Polignac number, because 28223505 - 2⁵ = 28223473 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (28223509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 104397 + ... + 104666.

It is an arithmetic number, because the mean of its divisors is an integer number (3135960).

Almost surely, 2^28223505 is an apocalyptic number.

It is an amenable number.

28223505 is a deficient number, since it is larger than the sum of its proper divisors (21951855).

28223505 is a wasteful number, since it uses less digits than its factorization.

28223505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209077 (or 209071 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 28223505 is about 5312.5798817524. The cubic root of 28223505 is about 304.4647244923.

Adding to 28223505 its reverse (50532282), we get a palindrome (78755787).

The spelling of 28223505 in words is "twenty-eight million, two hundred twenty-three thousand, five hundred five".