872840 has 16 divisors (see below), whose sum is σ = 1963980. Its totient is φ = 349120.

The previous prime is 872791. The next prime is 872843. The reversal of 872840 is 48278.

It can be written as a sum of positive squares in 2 ways, for example, as 872356 + 484 = 934^2 + 22^2 .

It is not an unprimeable number, because it can be changed into a prime (872843) by changing a digit.

872840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10871 + ... + 10950.

2⁸⁷²⁸⁴⁰ is an apocalyptic number.

It is an amenable number.

872840 is an abundant number, since it is smaller than the sum of its proper divisors (1091140).

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

872840 is a wasteful number, since it uses less digits than its factorization.

872840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21832 (or 21828 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 29.

The square root of 872840 is about 934.2590647139. The cubic root of 872840 is about 95.5677908336.

The spelling of 872840 in words is "eight hundred seventy-two thousand, eight hundred forty".