28140186 has 32 divisors (see below), whose sum is σ = 58480128. Its totient is φ = 9020160.

The previous prime is 28140143. The next prime is 28140187. The reversal of 28140186 is 68104182.

It is a super-2 number, since 2×28140186² = 1583740136229192, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28140187) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 17175 + ... + 18741.

It is an arithmetic number, because the mean of its divisors is an integer number (1827504).

Almost surely, 2^28140186 is an apocalyptic number.

28140186 is an abundant number, since it is smaller than the sum of its proper divisors (30339942).

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

28140186 is a wasteful number, since it uses less digits than its factorization.

28140186 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1686.

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 28140186 is about 5304.7324154947. The cubic root of 28140186 is about 304.1648243420.

The spelling of 28140186 in words is "twenty-eight million, one hundred forty thousand, one hundred eighty-six".