685769 has 4 divisors (see below), whose sum is σ = 783744. Its totient is φ = 587796.

The previous prime is 685759. The next prime is 685781. The reversal of 685769 is 967586.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 685769 - 2⁴ = 685753 is a prime.

It is a super-2 number, since 2×685769² = 940558242722, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 7.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 685769.

It is not an unprimeable number, because it can be changed into a prime (685739) 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 3 ways as a sum of consecutive naturals, for example, 48977 + ... + 48990.

It is an arithmetic number, because the mean of its divisors is an integer number (195936).

2⁶⁸⁵⁷⁶⁹ is an apocalyptic number.

It is an amenable number.

685769 is a deficient number, since it is larger than the sum of its proper divisors (97975).

685769 is an equidigital number, since it uses as much as digits as its factorization.

685769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97974.

The product of its digits is 90720, while the sum is 41.

The square root of 685769 is about 828.1117074405. Note that the first 3 decimals coincide. The cubic root of 685769 is about 88.1845730016.

The spelling of 685769 in words is "six hundred eighty-five thousand, seven hundred sixty-nine".