686866609 has 16 divisors (see below), whose sum is σ = 811036800. Its totient is φ = 573471360.

The previous prime is 686866577. The next prime is 686866619. The reversal of 686866609 is 906668686.

It is not a de Polignac number, because 686866609 - 2⁵ = 686866577 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 686866609.

It is not an unprimeable number, because it can be changed into a prime (686866619) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16389 + ... + 40525.

It is an arithmetic number, because the mean of its divisors is an integer number (50689800).

Almost surely, 2^686866609 is an apocalyptic number.

It is an amenable number.

686866609 is a deficient number, since it is larger than the sum of its proper divisors (124170191).

686866609 is a wasteful number, since it uses less digits than its factorization.

686866609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24360.

The product of its (nonzero) digits is 4478976, while the sum is 55.

The square root of 686866609 is about 26208.1401285936. The cubic root of 686866609 is about 882.3159592358.

The spelling of 686866609 in words is "six hundred eighty-six million, eight hundred sixty-six thousand, six hundred nine".