685611 has 16 divisors (see below), whose sum is σ = 1033600. Its totient is φ = 449064.

The previous prime is 685609. The next prime is 685613. The reversal of 685611 is 116586.

It is an interprime number because it is at equal distance from previous prime (685609) and next prime (685613).

It is not a de Polignac number, because 685611 - 2¹ = 685609 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 685611.

It is not an unprimeable number, because it can be changed into a prime (685613) 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 in 15 ways as a sum of consecutive naturals, for example, 1620 + ... + 1998.

It is an arithmetic number, because the mean of its divisors is an integer number (64600).

2⁶⁸⁵⁶¹¹ is an apocalyptic number.

685611 is a deficient number, since it is larger than the sum of its proper divisors (347989).

685611 is a wasteful number, since it uses less digits than its factorization.

685611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455 (or 449 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 685611 is about 828.0163041873. The cubic root of 685611 is about 88.1777999567.

Subtracting from 685611 its sum of digits (27), we obtain a square (685584 = 828²).

It can be divided in two parts, 685 and 611, that added together give a 4-th power (1296 = 6⁴).

The spelling of 685611 in words is "six hundred eighty-five thousand, six hundred eleven".