28389985 has 16 divisors (see below), whose sum is σ = 37956240. Its totient is φ = 20240640.

The previous prime is 28389979. The next prime is 28390001. The reversal of 28389985 is 58998382.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 331776 + 28058209 = 576^2 + 5297^2 .

It is not a de Polignac number, because 28389985 - 2¹¹ = 28387937 is a prime.

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 15 ways as a sum of consecutive naturals, for example, 5646 + ... + 9415.

It is an arithmetic number, because the mean of its divisors is an integer number (2372265).

Almost surely, 2^28389985 is an apocalyptic number.

It is an amenable number.

28389985 is a deficient number, since it is larger than the sum of its proper divisors (9566255).

28389985 is a wasteful number, since it uses less digits than its factorization.

28389985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15108.

The product of its digits is 1244160, while the sum is 52.

The square root of 28389985 is about 5328.2253143049. The cubic root of 28389985 is about 305.0621928177.

The spelling of 28389985 in words is "twenty-eight million, three hundred eighty-nine thousand, nine hundred eighty-five".