871605 has 24 divisors (see below), whose sum is σ = 1727232. Its totient is φ = 398304.

The previous prime is 871597. The next prime is 871613. The reversal of 871605 is 506178.

It is an interprime number because it is at equal distance from previous prime (871597) and next prime (871613).

It is not a de Polignac number, because 871605 - 2³ = 871597 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1069 + ... + 1698.

It is an arithmetic number, because the mean of its divisors is an integer number (71968).

2⁸⁷¹⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

871605 is a deficient number, since it is larger than the sum of its proper divisors (855627).

871605 is a wasteful number, since it uses less digits than its factorization.

871605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2785 (or 2782 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 871605 is about 933.5978791750. The cubic root of 871605 is about 95.5226959206.

The spelling of 871605 in words is "eight hundred seventy-one thousand, six hundred five".