685864 has 8 divisors (see below), whose sum is σ = 1286010. Its totient is φ = 342928.

The previous prime is 685859. The next prime is 685907. The reversal of 685864 is 468586.

685864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 476100 + 209764 = 690^2 + 458^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42859 + ... + 42874.

2⁶⁸⁵⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

685864 is a deficient number, since it is larger than the sum of its proper divisors (600146).

685864 is a wasteful number, since it uses less digits than its factorization.

685864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85739 (or 85735 counting only the distinct ones).

The product of its digits is 46080, while the sum is 37.

The square root of 685864 is about 828.1690648654. The cubic root of 685864 is about 88.1886449012.

The spelling of 685864 in words is "six hundred eighty-five thousand, eight hundred sixty-four".