28216212 has 12 divisors (see below), whose sum is σ = 65837856. Its totient is φ = 9405400.

The previous prime is 28216211. The next prime is 28216229. The reversal of 28216212 is 21261282.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28216211) 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 3 ways as a sum of consecutive naturals, for example, 1175664 + ... + 1175687.

It is an arithmetic number, because the mean of its divisors is an integer number (5486488).

Almost surely, 2^28216212 is an apocalyptic number.

It is an amenable number.

28216212 is an abundant number, since it is smaller than the sum of its proper divisors (37621644).

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

28216212 is a wasteful number, since it uses less digits than its factorization.

28216212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2351358 (or 2351356 counting only the distinct ones).

The product of its digits is 768, while the sum is 24.

The square root of 28216212 is about 5311.8934477265. The cubic root of 28216212 is about 304.4384975050.

Adding to 28216212 its reverse (21261282), we get a palindrome (49477494).

The spelling of 28216212 in words is "twenty-eight million, two hundred sixteen thousand, two hundred twelve".