840478 has 16 divisors (see below), whose sum is σ = 1338480. Its totient is φ = 395136.

The previous prime is 840473. The next prime is 840479. The reversal of 840478 is 874048.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (840473) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2326 + ... + 2662.

It is an arithmetic number, because the mean of its divisors is an integer number (83655).

2⁸⁴⁰⁴⁷⁸ is an apocalyptic number.

840478 is a deficient number, since it is larger than the sum of its proper divisors (498002).

840478 is a wasteful number, since it uses less digits than its factorization.

840478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411.

The product of its (nonzero) digits is 7168, while the sum is 31.

The square root of 840478 is about 916.7758722829. The cubic root of 840478 is about 94.3717734961.

The spelling of 840478 in words is "eight hundred forty thousand, four hundred seventy-eight".