871865 has 8 divisors (see below), whose sum is σ = 1072008. Its totient is φ = 680320.

The previous prime is 871837. The next prime is 871867. The reversal of 871865 is 568178.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 30976 + 840889 = 176^2 + 917^2 .

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

It is not a de Polignac number, because 871865 - 2¹⁶ = 806329 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (871867) 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, 1922 + ... + 2331.

It is an arithmetic number, because the mean of its divisors is an integer number (134001).

2⁸⁷¹⁸⁶⁵ is an apocalyptic number.

It is an amenable number.

871865 is a deficient number, since it is larger than the sum of its proper divisors (200143).

871865 is a wasteful number, since it uses less digits than its factorization.

871865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4299.

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

The square root of 871865 is about 933.7371150383. The cubic root of 871865 is about 95.5321931248.

The spelling of 871865 in words is "eight hundred seventy-one thousand, eight hundred sixty-five".