85640 has 16 divisors (see below), whose sum is σ = 192780. Its totient is φ = 34240.

The previous prime is 85639. The next prime is 85643. The reversal of 85640 is 4658.

It can be written as a sum of positive squares in 2 ways, for example, as 81796 + 3844 = 286^2 + 62^2 .

It is not an unprimeable number, because it can be changed into a prime (85643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1031 + ... + 1110.

2⁸⁵⁶⁴⁰ is an apocalyptic number.

It is an amenable number.

85640 is an abundant number, since it is smaller than the sum of its proper divisors (107140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96390).

85640 is a wasteful number, since it uses less digits than its factorization.

85640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2152 (or 2148 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 85640 is about 292.6431273753. The cubic root of 85640 is about 44.0783727165.

The spelling of 85640 in words is "eighty-five thousand, six hundred forty".