686668507 has 16 divisors (see below), whose sum is σ = 826624000. Its totient is φ = 569577960.

The previous prime is 686668487. The next prime is 686668511. The reversal of 686668507 is 705866686.

It is not a de Polignac number, because 686668507 - 2¹¹ = 686666459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686668517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21657 + ... + 42922.

It is an arithmetic number, because the mean of its divisors is an integer number (51664000).

Almost surely, 2^686668507 is an apocalyptic number.

686668507 is a deficient number, since it is larger than the sum of its proper divisors (139955493).

686668507 is an equidigital number, since it uses as much as digits as its factorization.

686668507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64631 (or 64617 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 52.

The square root of 686668507 is about 26204.3604577559. The cubic root of 686668507 is about 882.2311269649.

The spelling of 686668507 in words is "six hundred eighty-six million, six hundred sixty-eight thousand, five hundred seven".