28444821 has 8 divisors (see below), whose sum is σ = 38199840. Its totient is φ = 18826512.

The previous prime is 28444807. The next prime is 28444831. The reversal of 28444821 is 12844482.

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

It is not a de Polignac number, because 28444821 - 2⁹ = 28444309 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28444831) 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, 33690 + ... + 34523.

It is an arithmetic number, because the mean of its divisors is an integer number (4774980).

Almost surely, 2^28444821 is an apocalyptic number.

It is an amenable number.

28444821 is a deficient number, since it is larger than the sum of its proper divisors (9755019).

28444821 is a wasteful number, since it uses less digits than its factorization.

28444821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68355.

The product of its digits is 16384, while the sum is 33.

The square root of 28444821 is about 5333.3686352998. The cubic root of 28444821 is about 305.2584783682.

The spelling of 28444821 in words is "twenty-eight million, four hundred forty-four thousand, eight hundred twenty-one".