85811 has 8 divisors (see below), whose sum is σ = 97200. Its totient is φ = 75040.

The previous prime is 85793. The next prime is 85817. The reversal of 85811 is 11858.

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

It is a cyclic number.

It is not a de Polignac number, because 85811 - 2¹⁰ = 84787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 185 + ... + 453.

It is an arithmetic number, because the mean of its divisors is an integer number (12150).

2⁸⁵⁸¹¹ is an apocalyptic number.

85811 is a deficient number, since it is larger than the sum of its proper divisors (11389).

85811 is a wasteful number, since it uses less digits than its factorization.

85811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309.

The product of its digits is 320, while the sum is 23.

The square root of 85811 is about 292.9351464062. The cubic root of 85811 is about 44.1076907554.

Subtracting from 85811 its product of digits (320), we obtain a triangular number (85491 = T₄₁₃).

The spelling of 85811 in words is "eighty-five thousand, eight hundred eleven".