685445 has 4 divisors (see below), whose sum is σ = 822540. Its totient is φ = 548352.

The previous prime is 685429. The next prime is 685453. The reversal of 685445 is 544586.

685445 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 146689 + 538756 = 383^2 + 734^2 .

It is a cyclic number.

It is not a de Polignac number, because 685445 - 2⁴ = 685429 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68540 + ... + 68549.

It is an arithmetic number, because the mean of its divisors is an integer number (205635).

2⁶⁸⁵⁴⁴⁵ is an apocalyptic number.

It is an amenable number.

685445 is a deficient number, since it is larger than the sum of its proper divisors (137095).

685445 is a wasteful number, since it uses less digits than its factorization.

685445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137094.

The product of its digits is 19200, while the sum is 32.

The square root of 685445 is about 827.9160585470. The cubic root of 685445 is about 88.1706828517.

The spelling of 685445 in words is "six hundred eighty-five thousand, four hundred forty-five".