28220616 has 32 divisors (see below), whose sum is σ = 78391200. Its totient is φ = 9406800.

The previous prime is 28220611. The next prime is 28220623. The reversal of 28220616 is 61602282.

28220616 is a `hidden beast` number, since 28 + 2 + 20 + 616 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 28220616.

It is not an unprimeable number, because it can be changed into a prime (28220611) by changing a digit.

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, 65110 + ... + 65541.

It is an arithmetic number, because the mean of its divisors is an integer number (2449725).

Almost surely, 2^28220616 is an apocalyptic number.

It is an amenable number.

28220616 is an abundant number, since it is smaller than the sum of its proper divisors (50170584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28220616 is a wasteful number, since it uses less digits than its factorization.

28220616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130666 (or 130656 counting only the distinct ones).

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

The square root of 28220616 is about 5312.3079730001. The cubic root of 28220616 is about 304.4543356503.

Adding to 28220616 its reverse (61602282), we get a palindrome (89822898).

The spelling of 28220616 in words is "twenty-eight million, two hundred twenty thousand, six hundred sixteen".