840008 has 32 divisors (see below), whose sum is σ = 1746360. Its totient is φ = 376320.

The previous prime is 839999. The next prime is 840023. The reversal of 840008 is 800048.

840008 is nontrivially palindromic in base 7.

It can be written as a sum of positive squares in 4 ways, for example, as 611524 + 228484 = 782^2 + 478^2 .

It is a super-2 number, since 2×840008² = 1411226880128, which contains 22 as substring.

It is an unprimeable number.

840008 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, 4166 + ... + 4362.

2⁸⁴⁰⁰⁰⁸ 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 840008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (873180).

840008 is an abundant number, since it is smaller than the sum of its proper divisors (906352).

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

840008 is a wasteful number, since it uses less digits than its factorization.

840008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257 (or 253 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 840008 is about 916.5195033386. The cubic root of 840008 is about 94.3541791415.

The spelling of 840008 in words is "eight hundred forty thousand, eight".