28091244 has 12 divisors (see below), whose sum is σ = 65546264. Its totient is φ = 9363744.

The previous prime is 28091213. The next prime is 28091249. The reversal of 28091244 is 44219082.

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

It is not an unprimeable number, because it can be changed into a prime (28091249) 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, 1170457 + ... + 1170480.

Almost surely, 2^28091244 is an apocalyptic number.

It is an amenable number.

28091244 is an abundant number, since it is smaller than the sum of its proper divisors (37455020).

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

28091244 is a wasteful number, since it uses less digits than its factorization.

28091244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2340944 (or 2340942 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 28091244 is about 5300.1173571913. The cubic root of 28091244 is about 303.9883854058.

The spelling of 28091244 in words is "twenty-eight million, ninety-one thousand, two hundred forty-four".