871685 has 4 divisors (see below), whose sum is σ = 1046028. Its totient is φ = 697344.

The previous prime is 871681. The next prime is 871687. The reversal of 871685 is 586178.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 538756 + 332929 = 734^2 + 577^2 .

It is a cyclic number.

It is not a de Polignac number, because 871685 - 2² = 871681 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 871685.

It is not an unprimeable number, because it can be changed into a prime (871681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 87164 + ... + 87173.

It is an arithmetic number, because the mean of its divisors is an integer number (261507).

2⁸⁷¹⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

871685 is a deficient number, since it is larger than the sum of its proper divisors (174343).

871685 is a wasteful number, since it uses less digits than its factorization.

871685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174342.

The product of its digits is 13440, while the sum is 35.

The square root of 871685 is about 933.6407231907. The cubic root of 871685 is about 95.5256183384.

The spelling of 871685 in words is "eight hundred seventy-one thousand, six hundred eighty-five".