878005861 has 4 divisors (see below), whose sum is σ = 878143552. Its totient is φ = 877868172.

The previous prime is 878005853. The next prime is 878005873. The reversal of 878005861 is 168500878.

878005861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 878005861 - 2³ = 878005853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (878005831) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58791 + ... + 72196.

It is an arithmetic number, because the mean of its divisors is an integer number (219535888).

Almost surely, 2^878005861 is an apocalyptic number.

It is an amenable number.

878005861 is a deficient number, since it is larger than the sum of its proper divisors (137691).

878005861 is a wasteful number, since it uses less digits than its factorization.

878005861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137690.

The product of its (nonzero) digits is 107520, while the sum is 43.

The square root of 878005861 is about 29631.1636794777. The cubic root of 878005861 is about 957.5595787200.

The spelling of 878005861 in words is "eight hundred seventy-eight million, five thousand, eight hundred sixty-one".