840408 has 48 divisors (see below), whose sum is σ = 2240280. Its totient is φ = 262656.

The previous prime is 840353. The next prime is 840439. The reversal of 840408 is 804048.

840408 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a plaindrome in base 13.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8616 + ... + 8712.

2⁸⁴⁰⁴⁰⁸ 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 840408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1120140).

840408 is an abundant number, since it is smaller than the sum of its proper divisors (1399872).

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

840408 is a wasteful number, since it uses less digits than its factorization.

840408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144 (or 121 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 24.

The square root of 840408 is about 916.7376942179. The cubic root of 840408 is about 94.3691534761.

It can be divided in two parts, 84040 and 8, that added together give a palindrome (84048).

The spelling of 840408 in words is "eight hundred forty thousand, four hundred eight".