685618 has 8 divisors (see below), whose sum is σ = 1063980. Its totient is φ = 330960.

The previous prime is 685613. The next prime is 685621. The reversal of 685618 is 816586.

It is a happy number.

685618 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 2 ways, for example, as 660969 + 24649 = 813^2 + 157^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (685613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5853 + ... + 5968.

2⁶⁸⁵⁶¹⁸ is an apocalyptic number.

685618 is a deficient number, since it is larger than the sum of its proper divisors (378362).

685618 is a wasteful number, since it uses less digits than its factorization.

685618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11852.

The product of its digits is 11520, while the sum is 34.

The square root of 685618 is about 828.0205311464. The cubic root of 685618 is about 88.1781000503.

Subtracting from 685618 its sum of digits (34), we obtain a square (685584 = 828²).

The spelling of 685618 in words is "six hundred eighty-five thousand, six hundred eighteen".