840144 has 40 divisors (see below), whose sum is σ = 2267712. Its totient is φ = 267520.

The previous prime is 840139. The next prime is 840149. The reversal of 840144 is 441048.

It is an interprime number because it is at equal distance from previous prime (840139) and next prime (840149).

It is a self number, because there is not a number n which added to its sum of digits gives 840144.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 840144.

It is not an unprimeable number, because it can be changed into a prime (840149) by changing a digit.

840144 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 7 ways as a sum of consecutive naturals, for example, 724 + ... + 1484.

2⁸⁴⁰¹⁴⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 840144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1133856).

840144 is an abundant number, since it is smaller than the sum of its proper divisors (1427568).

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

840144 is a wasteful number, since it uses less digits than its factorization.

840144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 795 (or 789 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 840144 is about 916.5936940652. The cubic root of 840144 is about 94.3592709485.

The spelling of 840144 in words is "eight hundred forty thousand, one hundred forty-four".