28222209 has 16 divisors (see below), whose sum is σ = 42437440. Its totient is φ = 18532800.

The previous prime is 28222177. The next prime is 28222217. The reversal of 28222209 is 90222282.

It is not a de Polignac number, because 28222209 - 2⁵ = 28222177 is a prime.

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

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28222279) 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, 5992 + ... + 9609.

It is an arithmetic number, because the mean of its divisors is an integer number (2652340).

Almost surely, 2^28222209 is an apocalyptic number.

It is an amenable number.

28222209 is a deficient number, since it is larger than the sum of its proper divisors (14215231).

28222209 is a wasteful number, since it uses less digits than its factorization.

28222209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15677 (or 15671 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 28222209 is about 5312.4579057156. The cubic root of 28222209 is about 304.4600641649.

The spelling of 28222209 in words is "twenty-eight million, two hundred twenty-two thousand, two hundred nine".