686930209 has 8 divisors (see below), whose sum is σ = 810387968. Its totient is φ = 569803680.

The previous prime is 686930207. The next prime is 686930261. The reversal of 686930209 is 902039686.

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 686930209 - 2¹ = 686930207 is a prime.

It is a super-2 number, since 2×686930209² = 943746224073567362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686930207) 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, 1582572 + ... + 1583005.

It is an arithmetic number, because the mean of its divisors is an integer number (101298496).

Almost surely, 2^686930209 is an apocalyptic number.

It is an amenable number.

686930209 is a deficient number, since it is larger than the sum of its proper divisors (123457759).

686930209 is a wasteful number, since it uses less digits than its factorization.

686930209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3165615.

The product of its (nonzero) digits is 139968, while the sum is 43.

The square root of 686930209 is about 26209.3534639830. The cubic root of 686930209 is about 882.3431909003.

The spelling of 686930209 in words is "six hundred eighty-six million, nine hundred thirty thousand, two hundred nine".