686138064 has 40 divisors (see below), whose sum is σ = 1820434080. Its totient is φ = 222530688.

The previous prime is 686138041. The next prime is 686138069. The reversal of 686138064 is 460831686.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686138069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 191394 + ... + 194945.

It is an arithmetic number, because the mean of its divisors is an integer number (45510852).

Almost surely, 2^686138064 is an apocalyptic number.

It is an amenable number.

686138064 is an abundant number, since it is smaller than the sum of its proper divisors (1134296016).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

686138064 is a wasteful number, since it uses less digits than its factorization.

686138064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 386387 (or 386381 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 686138064 is about 26194.2372288257. The cubic root of 686138064 is about 882.0038975358.

The spelling of 686138064 in words is "six hundred eighty-six million, one hundred thirty-eight thousand, sixty-four".