28185861 has 12 divisors (see below), whose sum is σ = 41308736. Its totient is φ = 17082120.

The previous prime is 28185841. The next prime is 28185907. The reversal of 28185861 is 16858182.

It is not a de Polignac number, because 28185861 - 2⁷ = 28185733 is a prime.

It is a super-2 number, since 2×28185861² = 1588885520622642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28185821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38461 + ... + 39186.

Almost surely, 2^28185861 is an apocalyptic number.

It is an amenable number.

28185861 is a deficient number, since it is larger than the sum of its proper divisors (13122875).

28185861 is a wasteful number, since it uses less digits than its factorization.

28185861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77672 (or 77661 counting only the distinct ones).

The product of its digits is 30720, while the sum is 39.

The square root of 28185861 is about 5309.0357881634. The cubic root of 28185861 is about 304.3293010869.

The spelling of 28185861 in words is "twenty-eight million, one hundred eighty-five thousand, eight hundred sixty-one".