28165986 has 12 divisors (see below), whose sum is σ = 61026342. Its totient is φ = 9388656.

The previous prime is 28165981. The next prime is 28165997. The reversal of 28165986 is 68956182.

It can be written as a sum of positive squares in only one way, i.e., 25190361 + 2975625 = 5019^2 + 1725^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28165981) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 782371 + ... + 782406.

Almost surely, 2^28165986 is an apocalyptic number.

28165986 is an abundant number, since it is smaller than the sum of its proper divisors (32860356).

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

28165986 is a wasteful number, since it uses less digits than its factorization.

28165986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564785 (or 1564782 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The square root of 28165986 is about 5307.1636492575. The cubic root of 28165986 is about 304.2577526001.

The spelling of 28165986 in words is "twenty-eight million, one hundred sixty-five thousand, nine hundred eighty-six".