685578 has 16 divisors (see below), whose sum is σ = 1381536. Its totient is φ = 226800.

The previous prime is 685547. The next prime is 685591. The reversal of 685578 is 875586.

It is a happy number.

It is a Curzon number.

It is a plaindrome in base 14.

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, 628 + ... + 1328.

It is an arithmetic number, because the mean of its divisors is an integer number (86346).

2⁶⁸⁵⁵⁷⁸ is an apocalyptic number.

685578 is an abundant number, since it is smaller than the sum of its proper divisors (695958).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

685578 is a wasteful number, since it uses less digits than its factorization.

685578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 869.

The product of its digits is 67200, while the sum is 39.

The square root of 685578 is about 827.9963768037. The cubic root of 685578 is about 88.1763852020.

The spelling of 685578 in words is "six hundred eighty-five thousand, five hundred seventy-eight".