28381365 has 24 divisors (see below), whose sum is σ = 49417368. Its totient is φ = 15068160.

The previous prime is 28381351. The next prime is 28381403. The reversal of 28381365 is 56318382.

It can be written as a sum of positive squares in 4 ways, for example, as 13704804 + 14676561 = 3702^2 + 3831^2 .

It is not a de Polignac number, because 28381365 - 2⁴ = 28381349 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9537 + ... + 12153.

It is an arithmetic number, because the mean of its divisors is an integer number (2059057).

Almost surely, 2^28381365 is an apocalyptic number.

It is an amenable number.

28381365 is a deficient number, since it is larger than the sum of its proper divisors (21036003).

28381365 is a wasteful number, since it uses less digits than its factorization.

28381365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2869 (or 2866 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 28381365 is about 5327.4163531678. The cubic root of 28381365 is about 305.0313145309.

The spelling of 28381365 in words is "twenty-eight million, three hundred eighty-one thousand, three hundred sixty-five".