686564 has 6 divisors (see below), whose sum is σ = 1201494. Its totient is φ = 343280.

The previous prime is 686563. The next prime is 686593. The reversal of 686564 is 465686.

It can be written as a sum of positive squares in only one way, i.e., 532900 + 153664 = 730^2 + 392^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 686564.

It is not an unprimeable number, because it can be changed into a prime (686563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 85817 + ... + 85824.

It is an arithmetic number, because the mean of its divisors is an integer number (200249).

2⁶⁸⁶⁵⁶⁴ is an apocalyptic number.

It is an amenable number.

686564 is a deficient number, since it is larger than the sum of its proper divisors (514930).

686564 is a wasteful number, since it uses less digits than its factorization.

686564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171645 (or 171643 counting only the distinct ones).

The product of its digits is 34560, while the sum is 35.

The square root of 686564 is about 828.5915761097. The cubic root of 686564 is about 88.2186367859.

The spelling of 686564 in words is "six hundred eighty-six thousand, five hundred sixty-four".