28563216 has 80 divisors (see below), whose sum is σ = 82280448. Its totient is φ = 8464000.

The previous prime is 28563211. The next prime is 28563253. The reversal of 28563216 is 61236582.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (28563211) 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 15 ways as a sum of consecutive naturals, for example, 24241 + ... + 25391.

Almost surely, 2^28563216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28563216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41140224).

28563216 is an abundant number, since it is smaller than the sum of its proper divisors (53717232).

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

28563216 is a wasteful number, since it uses less digits than its factorization.

28563216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1220 (or 1214 counting only the distinct ones).

The product of its digits is 17280, while the sum is 33.

The square root of 28563216 is about 5344.4565673228. The cubic root of 28563216 is about 305.6814147639.

Adding to 28563216 its reverse (61236582), we get a palindrome (89799798).

The spelling of 28563216 in words is "twenty-eight million, five hundred sixty-three thousand, two hundred sixteen".