686629334161 has 27 divisors (see below), whose sum is σ = 739944154929. Its totient is φ = 637024996608.

The previous prime is 686629334147. The next prime is 686629334179. The reversal of 686629334161 is 161433926686.

It is a happy number.

The square root of 686629334161 is 828631.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 67512148561 + 619117185600 = 259831^2 + 786840^2 .

It is not a de Polignac number, because 686629334161 - 2⁷ = 686629334033 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686629334141) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1112851125 + ... + 1112851741.

Almost surely, 2^686629334161 is an apocalyptic number.

686629334161 is the 828631-st square number.

686629334161 is the 414316-th centered octagonal number.

It is an amenable number.

686629334161 is a deficient number, since it is larger than the sum of its proper divisors (53314820768).

686629334161 is an frugal number, since it uses more digits than its factorization.

686629334161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1426 (or 713 counting only the distinct ones).

The product of its digits is 6718464, while the sum is 55.

The spelling of 686629334161 in words is "six hundred eighty-six billion, six hundred twenty-nine million, three hundred thirty-four thousand, one hundred sixty-one".