28686321 has 12 divisors (see below), whose sum is σ = 41518672. Its totient is φ = 19085976.

The previous prime is 28686271. The next prime is 28686367. The reversal of 28686321 is 12368682.

It is not a de Polignac number, because 28686321 - 2⁷ = 28686193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28682321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2010 + ... + 7836.

Almost surely, 2^28686321 is an apocalyptic number.

It is an amenable number.

28686321 is a deficient number, since it is larger than the sum of its proper divisors (12832351).

28686321 is a wasteful number, since it uses less digits than its factorization.

28686321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6380 (or 6377 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 28686321 is about 5355.9612582617. The cubic root of 28686321 is about 306.1199388858.

The spelling of 28686321 in words is "twenty-eight million, six hundred eighty-six thousand, three hundred twenty-one".