685565 has 8 divisors (see below), whose sum is σ = 849408. Its totient is φ = 530640.

The previous prime is 685547. The next prime is 685591. The reversal of 685565 is 565586.

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

It is not a de Polignac number, because 685565 - 2¹⁴ = 669181 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2057 + ... + 2366.

It is an arithmetic number, because the mean of its divisors is an integer number (106176).

2⁶⁸⁵⁵⁶⁵ is an apocalyptic number.

It is an amenable number.

685565 is a deficient number, since it is larger than the sum of its proper divisors (163843).

685565 is a wasteful number, since it uses less digits than its factorization.

685565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4459.

The product of its digits is 36000, while the sum is 35.

The square root of 685565 is about 827.9885264906. The cubic root of 685565 is about 88.1758278620.

The spelling of 685565 in words is "six hundred eighty-five thousand, five hundred sixty-five".