28186866 has 20 divisors (see below), whose sum is σ = 63159822. Its totient is φ = 9395568.

The previous prime is 28186849. The next prime is 28186871. The reversal of 28186866 is 66868182.

It can be written as a sum of positive squares in only one way, i.e., 22325625 + 5861241 = 4725^2 + 2421^2 .

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 9 ways as a sum of consecutive naturals, for example, 86835 + ... + 87158.

Almost surely, 2^28186866 is an apocalyptic number.

28186866 is an abundant number, since it is smaller than the sum of its proper divisors (34972956).

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

28186866 is a wasteful number, since it uses less digits than its factorization.

28186866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174007 (or 173998 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 28186866 is about 5309.1304372750. The cubic root of 28186866 is about 304.3329181169.

The spelling of 28186866 in words is "twenty-eight million, one hundred eighty-six thousand, eight hundred sixty-six".