871820 has 12 divisors (see below), whose sum is σ = 1830864. Its totient is φ = 348720.

The previous prime is 871817. The next prime is 871823. The reversal of 871820 is 28178.

871820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (871817) and next prime (871823).

It is a super-2 number, since 2×871820² = 1520140224800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 871820.

It is not an unprimeable number, because it can be changed into a prime (871823) 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, 21776 + ... + 21815.

It is an arithmetic number, because the mean of its divisors is an integer number (152572).

2⁸⁷¹⁸²⁰ is an apocalyptic number.

It is an amenable number.

871820 is an abundant number, since it is smaller than the sum of its proper divisors (959044).

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

871820 is a wasteful number, since it uses less digits than its factorization.

871820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43600 (or 43598 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 26.

The square root of 871820 is about 933.7130180093. The cubic root of 871820 is about 95.5305495130.

Adding to 871820 its reverse (28178), we get a palindrome (899998).

The spelling of 871820 in words is "eight hundred seventy-one thousand, eight hundred twenty".