686505878 has 16 divisors (see below), whose sum is σ = 1039100400. Its totient is φ = 340150176.

The previous prime is 686505847. The next prime is 686505907. The reversal of 686505878 is 878505686.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136700 + ... + 141632.

It is an arithmetic number, because the mean of its divisors is an integer number (64943775).

Almost surely, 2^686505878 is an apocalyptic number.

686505878 is a deficient number, since it is larger than the sum of its proper divisors (352594522).

686505878 is a wasteful number, since it uses less digits than its factorization.

686505878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5551.

The product of its (nonzero) digits is 3225600, while the sum is 53.

The square root of 686505878 is about 26201.2571835780. The cubic root of 686505878 is about 882.1614729311.

The spelling of 686505878 in words is "six hundred eighty-six million, five hundred five thousand, eight hundred seventy-eight".