28688566 has 8 divisors (see below), whose sum is σ = 43197264. Its totient is φ = 14289480.

The previous prime is 28688557. The next prime is 28688587. The reversal of 28688566 is 66588682.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

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, 26745 + ... + 27796.

It is an arithmetic number, because the mean of its divisors is an integer number (5399658).

Almost surely, 2^28688566 is an apocalyptic number.

28688566 is a deficient number, since it is larger than the sum of its proper divisors (14508698).

28688566 is a wasteful number, since it uses less digits than its factorization.

28688566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54806.

The product of its digits is 1105920, while the sum is 49.

The square root of 28688566 is about 5356.1708337207. The cubic root of 28688566 is about 306.1279243566.

The spelling of 28688566 in words is "twenty-eight million, six hundred eighty-eight thousand, five hundred sixty-six".