840028 has 24 divisors (see below), whose sum is σ = 1769600. Its totient is φ = 340848.

The previous prime is 840023. The next prime is 840053. The reversal of 840028 is 820048.

840028 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 839990 and 840008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840023) 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, 258 + ... + 1321.

2⁸⁴⁰⁰²⁸ is an apocalyptic number.

It is an amenable number.

840028 is an abundant number, since it is smaller than the sum of its proper divisors (929572).

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

840028 is a wasteful number, since it uses less digits than its factorization.

840028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1609 (or 1607 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 22.

The square root of 840028 is about 916.5304141162. The cubic root of 840028 is about 94.3549279711.

The spelling of 840028 in words is "eight hundred forty thousand, twenty-eight".