686540178 has 32 divisors (see below), whose sum is σ = 1544966400. Its totient is φ = 225948528.

The previous prime is 686540161. The next prime is 686540191. The reversal of 686540178 is 871045686.

It is a happy number.

686540178 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76201 + ... + 84732.

It is an arithmetic number, because the mean of its divisors is an integer number (48280200).

Almost surely, 2^686540178 is an apocalyptic number.

686540178 is an abundant number, since it is smaller than the sum of its proper divisors (858426222).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

686540178 is a wasteful number, since it uses less digits than its factorization.

686540178 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161023 (or 161017 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The square root of 686540178 is about 26201.9117241472. The cubic root of 686540178 is about 882.1761645434.

The spelling of 686540178 in words is "six hundred eighty-six million, five hundred forty thousand, one hundred seventy-eight".