686309220872 has 36 divisors (see below), whose sum is σ = 1414502395215. Its totient is φ = 311947020880.

The previous prime is 686309220871. The next prime is 686309220881. The reversal of 686309220872 is 278022903686.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

686309220872 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 343154610436 + 343154610436 = 585794^2 + 585794^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=585794.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686309220871) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 25761623 + ... + 25788249.

Almost surely, 2^686309220872 is an apocalyptic number.

It is an amenable number.

686309220872 is an abundant number, since it is smaller than the sum of its proper divisors (728193174343).

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

686309220872 is an frugal number, since it uses more digits than its factorization.

686309220872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53282 (or 26640 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 53.

The spelling of 686309220872 in words is "six hundred eighty-six billion, three hundred nine million, two hundred twenty thousand, eight hundred seventy-two".