685913 has 4 divisors (see below), whose sum is σ = 688548. Its totient is φ = 683280.

The previous prime is 685907. The next prime is 685939. The reversal of 685913 is 319586.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 319586 = 2 ⋅159793.

It can be written as a sum of positive squares in 2 ways, for example, as 565504 + 120409 = 752^2 + 347^2 .

It is a cyclic number.

It is not a de Polignac number, because 685913 - 2⁶ = 685849 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 685913.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 685913.

It is not an unprimeable number, because it can be changed into a prime (685963) 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, 878 + ... + 1463.

It is an arithmetic number, because the mean of its divisors is an integer number (172137).

2⁶⁸⁵⁹¹³ is an apocalyptic number.

It is an amenable number.

685913 is a deficient number, since it is larger than the sum of its proper divisors (2635).

685913 is a wasteful number, since it uses less digits than its factorization.

685913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2634.

The product of its digits is 6480, while the sum is 32.

The square root of 685913 is about 828.1986476685. The cubic root of 685913 is about 88.1907449972.

The spelling of 685913 in words is "six hundred eighty-five thousand, nine hundred thirteen".