686909678 has 32 divisors (see below), whose sum is σ = 1280487936. Its totient is φ = 269098848.

The previous prime is 686909677. The next prime is 686909681. The reversal of 686909678 is 876909686.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686909677) 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, 425 + ... + 37067.

It is an arithmetic number, because the mean of its divisors is an integer number (40015248).

Almost surely, 2^686909678 is an apocalyptic number.

686909678 is a deficient number, since it is larger than the sum of its proper divisors (593578258).

686909678 is a wasteful number, since it uses less digits than its factorization.

686909678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36768.

The product of its (nonzero) digits is 7838208, while the sum is 59.

The square root of 686909678 is about 26208.9617879076. The cubic root of 686909678 is about 882.3344003088.

The spelling of 686909678 in words is "six hundred eighty-six million, nine hundred nine thousand, six hundred seventy-eight".