878905 has 4 divisors (see below), whose sum is σ = 1054692. Its totient is φ = 703120.

The previous prime is 878893. The next prime is 878929. The reversal of 878905 is 509878.

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

It can be written as a sum of positive squares in 2 ways, for example, as 364816 + 514089 = 604^2 + 717^2 .

It is not a de Polignac number, because 878905 - 2⁵ = 878873 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

878905 is a lucky number.

It is a nialpdrome in base 5.

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 in 3 ways as a sum of consecutive naturals, for example, 87886 + ... + 87895.

It is an arithmetic number, because the mean of its divisors is an integer number (263673).

2⁸⁷⁸⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

878905 is a deficient number, since it is larger than the sum of its proper divisors (175787).

878905 is a wasteful number, since it uses less digits than its factorization.

878905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175786.

The product of its (nonzero) digits is 20160, while the sum is 37.

The square root of 878905 is about 937.4993333331. The cubic root of 878905 is about 95.7886336382.

The spelling of 878905 in words is "eight hundred seventy-eight thousand, nine hundred five".