840878 has 4 divisors (see below), whose sum is σ = 1261320. Its totient is φ = 420438.

The previous prime is 840863. The next prime is 840907. The reversal of 840878 is 878048.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 210218 + ... + 210221.

It is an arithmetic number, because the mean of its divisors is an integer number (315330).

2⁸⁴⁰⁸⁷⁸ is an apocalyptic number.

840878 is a deficient number, since it is larger than the sum of its proper divisors (420442).

840878 is a wasteful number, since it uses less digits than its factorization.

840878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420441.

The product of its (nonzero) digits is 14336, while the sum is 35.

The square root of 840878 is about 916.9940021614. The cubic root of 840878 is about 94.3867422490.

The spelling of 840878 in words is "eight hundred forty thousand, eight hundred seventy-eight".