686627818685 has 8 divisors (see below), whose sum is σ = 826028834136. Its totient is φ = 547918620480.

The previous prime is 686627818631. The next prime is 686627818691. The reversal of 686627818685 is 586818726686.

It can be written as a sum of positive squares in 4 ways, for example, as 94309795801 + 592318022884 = 307099^2 + 769622^2 .

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

It is not a de Polignac number, because 686627818685 - 2¹⁸ = 686627556541 is a prime.

It is a super-2 number, since 2×686627818685² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 172952126 + ... + 172956095.

It is an arithmetic number, because the mean of its divisors is an integer number (103253604267).

Almost surely, 2^686627818685 is an apocalyptic number.

It is an amenable number.

686627818685 is a deficient number, since it is larger than the sum of its proper divisors (139401015451).

686627818685 is a wasteful number, since it uses less digits than its factorization.

686627818685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 345908623.

The product of its digits is 371589120, while the sum is 71.

The spelling of 686627818685 in words is "six hundred eighty-six billion, six hundred twenty-seven million, eight hundred eighteen thousand, six hundred eighty-five".