28689588 has 18 divisors (see below), whose sum is σ = 72520994. Its totient is φ = 9563184.

The previous prime is 28689587. The next prime is 28689607. The reversal of 28689588 is 88598682.

It can be written as a sum of positive squares in only one way, i.e., 25826724 + 2862864 = 5082^2 + 1692^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28689587) 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 5 ways as a sum of consecutive naturals, for example, 398431 + ... + 398502.

Almost surely, 2^28689588 is an apocalyptic number.

It is an amenable number.

28689588 is an abundant number, since it is smaller than the sum of its proper divisors (43831406).

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

28689588 is a wasteful number, since it uses less digits than its factorization.

28689588 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 796943 (or 796938 counting only the distinct ones).

The product of its digits is 2211840, while the sum is 54.

The square root of 28689588 is about 5356.2662368482. The cubic root of 28689588 is about 306.1315594753.

The spelling of 28689588 in words is "twenty-eight million, six hundred eighty-nine thousand, five hundred eighty-eight".