686686018369 has 8 divisors (see below), whose sum is σ = 746829882792. Its totient is φ = 627588134400.

The previous prime is 686686018367. The next prime is 686686018387. The reversal of 686686018369 is 963810686686.

It can be written as a sum of positive squares in 4 ways, for example, as 259578022144 + 427107996225 = 509488^2 + 653535^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 686686018369 - 2¹ = 686686018367 is a prime.

It is a super-2 number, since 2×686686018369² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686686018367) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 261493744 + ... + 261496369.

It is an arithmetic number, because the mean of its divisors is an integer number (93353735349).

Almost surely, 2^686686018369 is an apocalyptic number.

It is an amenable number.

686686018369 is a deficient number, since it is larger than the sum of its proper divisors (60143864423).

686686018369 is a wasteful number, since it uses less digits than its factorization.

686686018369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522990227.

The product of its (nonzero) digits is 107495424, while the sum is 67.

The spelling of 686686018369 in words is "six hundred eighty-six billion, six hundred eighty-six million, eighteen thousand, three hundred sixty-nine".