28005189 has 16 divisors (see below), whose sum is σ = 38617728. Its totient is φ = 18038592.

The previous prime is 28005163. The next prime is 28005199. The reversal of 28005189 is 98150082.

It is a happy number.

It is not a de Polignac number, because 28005189 - 2¹¹ = 28003141 is a prime.

It is a super-2 number, since 2×28005189² = 1568581221851442, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28005139) 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, 16624 + ... + 18230.

It is an arithmetic number, because the mean of its divisors is an integer number (2413608).

Almost surely, 2^28005189 is an apocalyptic number.

It is an amenable number.

28005189 is a deficient number, since it is larger than the sum of its proper divisors (10612539).

28005189 is a wasteful number, since it uses less digits than its factorization.

28005189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1804.

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 28005189 is about 5291.9929138275. The cubic root of 28005189 is about 303.6776541958.

The spelling of 28005189 in words is "twenty-eight million, five thousand, one hundred eighty-nine".