28364221 has 8 divisors (see below), whose sum is σ = 29652480. Its totient is φ = 27080592.

The previous prime is 28364213. The next prime is 28364227. The reversal of 28364221 is 12246382.

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

It is a cyclic number.

It is not a de Polignac number, because 28364221 - 2³ = 28364213 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28364221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28364227) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19135 + ... + 20563.

It is an arithmetic number, because the mean of its divisors is an integer number (3706560).

Almost surely, 2^28364221 is an apocalyptic number.

It is an amenable number.

28364221 is a deficient number, since it is larger than the sum of its proper divisors (1288259).

28364221 is a wasteful number, since it uses less digits than its factorization.

28364221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2315.

The product of its digits is 4608, while the sum is 28.

The square root of 28364221 is about 5325.8070749887. The cubic root of 28364221 is about 304.9698832576.

The spelling of 28364221 in words is "twenty-eight million, three hundred sixty-four thousand, two hundred twenty-one".