871638 has 16 divisors (see below), whose sum is σ = 1776816. Its totient is φ = 284960.

The previous prime is 871621. The next prime is 871639. The reversal of 871638 is 836178.

It is a junction number, because it is equal to n+sod(n) for n = 871599 and 871608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (871639) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1053 + ... + 1688.

It is an arithmetic number, because the mean of its divisors is an integer number (111051).

2⁸⁷¹⁶³⁸ is an apocalyptic number.

871638 is an abundant number, since it is smaller than the sum of its proper divisors (905178).

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

871638 is a wasteful number, since it uses less digits than its factorization.

871638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2799.

The product of its digits is 8064, while the sum is 33.

The square root of 871638 is about 933.6155525697. The cubic root of 871638 is about 95.5239014397.

The spelling of 871638 in words is "eight hundred seventy-one thousand, six hundred thirty-eight".