28289686 has 4 divisors (see below), whose sum is σ = 42434532. Its totient is φ = 14144842.

The previous prime is 28289669. The next prime is 28289687. The reversal of 28289686 is 68698282.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28289687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7072420 + ... + 7072423.

It is an arithmetic number, because the mean of its divisors is an integer number (10608633).

Almost surely, 2^28289686 is an apocalyptic number.

28289686 is a deficient number, since it is larger than the sum of its proper divisors (14144846).

28289686 is a wasteful number, since it uses less digits than its factorization.

28289686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14144845.

The product of its digits is 663552, while the sum is 49.

The square root of 28289686 is about 5318.8049409618. The cubic root of 28289686 is about 304.7025174329.

The spelling of 28289686 in words is "twenty-eight million, two hundred eighty-nine thousand, six hundred eighty-six".