28185717 has 8 divisors (see below), whose sum is σ = 42949696. Its totient is φ = 16106112.

The previous prime is 28185713. The next prime is 28185719. The reversal of 28185717 is 71758182.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28185717 - 2² = 28185713 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28185713) 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 7 ways as a sum of consecutive naturals, for example, 671068 + ... + 671109.

It is an arithmetic number, because the mean of its divisors is an integer number (5368712).

Almost surely, 2^28185717 is an apocalyptic number.

It is an amenable number.

28185717 is a deficient number, since it is larger than the sum of its proper divisors (14763979).

28185717 is a wasteful number, since it uses less digits than its factorization.

28185717 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1342187.

The product of its digits is 31360, while the sum is 39.

The square root of 28185717 is about 5309.0222263615. The cubic root of 28185717 is about 304.3287828188.

It can be divided in two parts, 28 and 185717, that added together give a triangular number (185745 = T₆₀₉).

The spelling of 28185717 in words is "twenty-eight million, one hundred eighty-five thousand, seven hundred seventeen".