28516689 has 24 divisors (see below), whose sum is σ = 42642600. Its totient is φ = 18351360.

The previous prime is 28516681. The next prime is 28516693. The reversal of 28516689 is 98661582.

It can be written as a sum of positive squares in 4 ways, for example, as 1089 + 28515600 = 33^2 + 5340^2 .

It is not a de Polignac number, because 28516689 - 2³ = 28516681 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28516681) by changing a digit.

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, 39867 + ... + 40575.

It is an arithmetic number, because the mean of its divisors is an integer number (1776775).

Almost surely, 2^28516689 is an apocalyptic number.

It is an amenable number.

28516689 is a deficient number, since it is larger than the sum of its proper divisors (14125911).

28516689 is a wasteful number, since it uses less digits than its factorization.

28516689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 865 (or 862 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The square root of 28516689 is about 5340.1019653186. The cubic root of 28516689 is about 305.5153483967.

The spelling of 28516689 in words is "twenty-eight million, five hundred sixteen thousand, six hundred eighty-nine".