28088821 has 16 divisors (see below), whose sum is σ = 30883840. Its totient is φ = 25446960.

The previous prime is 28088803. The next prime is 28088833. The reversal of 28088821 is 12888082.

It is a cyclic number.

It is not a de Polignac number, because 28088821 - 2⁵ = 28088789 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28088861) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60436 + ... + 60898.

It is an arithmetic number, because the mean of its divisors is an integer number (1930240).

Almost surely, 2^28088821 is an apocalyptic number.

It is an amenable number.

28088821 is a deficient number, since it is larger than the sum of its proper divisors (2795019).

28088821 is a wasteful number, since it uses less digits than its factorization.

28088821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 616.

The product of its (nonzero) digits is 16384, while the sum is 37.

The square root of 28088821 is about 5299.8887724178. Note that the first 3 decimals coincide. The cubic root of 28088821 is about 303.9796450187.

The spelling of 28088821 in words is "twenty-eight million, eighty-eight thousand, eight hundred twenty-one".