686916 has 18 divisors (see below), whose sum is σ = 1736462. Its totient is φ = 228960.

The previous prime is 686911. The next prime is 686947. The reversal of 686916 is 619686.

686916 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 484416 + 202500 = 696^2 + 450^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 19081 = 686916 / (6 + 8 + 6 + 9 + 1 + 6).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 686916.

It is not an unprimeable number, because it can be changed into a prime (686911) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9505 + ... + 9576.

2⁶⁸⁶⁹¹⁶ is an apocalyptic number.

It is an amenable number.

686916 is an abundant number, since it is smaller than the sum of its proper divisors (1049546).

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

686916 is a wasteful number, since it uses less digits than its factorization.

686916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19091 (or 19086 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 686916 is about 828.8039575195. The cubic root of 686916 is about 88.2337107167.

The spelling of 686916 in words is "six hundred eighty-six thousand, nine hundred sixteen".