85905 has 24 divisors (see below), whose sum is σ = 157248. Its totient is φ = 43296.

The previous prime is 85903. The next prime is 85909. The reversal of 85905 is 50958.

85905 is a nontrivial binomial coefficient, being equal to C(415, 2).

It is not a de Polignac number, because 85905 - 2¹ = 85903 is a prime.

It is a Smith number, since the sum of its digits (27) 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 (85903) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 994 + ... + 1076.

It is an arithmetic number, because the mean of its divisors is an integer number (6552).

2⁸⁵⁹⁰⁵ is an apocalyptic number.

85905 is the 414-th triangular number.

It is an amenable number.

85905 is a deficient number, since it is larger than the sum of its proper divisors (71343).

85905 is a wasteful number, since it uses less digits than its factorization.

85905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 85905 is about 293.0955475609. The cubic root of 85905 is about 44.1237905170.

It can be divided in two parts, 85 and 905, that added together give a triangular number (990 = T₄₄).

The spelling of 85905 in words is "eighty-five thousand, nine hundred five".