686668880 has 20 divisors (see below), whose sum is σ = 1596505332. Its totient is φ = 274667520.

The previous prime is 686668847. The next prime is 686668883. The reversal of 686668880 is 88866686.

686668880 is digitally balanced in base 2 and base 6, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 164454976 + 522213904 = 12824^2 + 22852^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686668883) 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, 4291601 + ... + 4291760.

Almost surely, 2^686668880 is an apocalyptic number.

It is an amenable number.

686668880 is an abundant number, since it is smaller than the sum of its proper divisors (909836452).

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

686668880 is a wasteful number, since it uses less digits than its factorization.

686668880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8583374 (or 8583368 counting only the distinct ones).

The product of its (nonzero) digits is 5308416, while the sum is 56.

The square root of 686668880 is about 26204.3675748910. The cubic root of 686668880 is about 882.2312867083.

The spelling of 686668880 in words is "six hundred eighty-six million, six hundred sixty-eight thousand, eight hundred eighty".