684985 has 8 divisors (see below), whose sum is σ = 939456. Its totient is φ = 469680.

The previous prime is 684977. The next prime is 684989. The reversal of 684985 is 589486.

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

It is not a de Polignac number, because 684985 - 2³ = 684977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (684989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9751 + ... + 9820.

It is an arithmetic number, because the mean of its divisors is an integer number (117432).

2⁶⁸⁴⁹⁸⁵ is an apocalyptic number.

It is an amenable number.

684985 is a deficient number, since it is larger than the sum of its proper divisors (254471).

684985 is a wasteful number, since it uses less digits than its factorization.

684985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19583.

The product of its digits is 69120, while the sum is 40.

The square root of 684985 is about 827.6382059813. The cubic root of 684985 is about 88.1509547479.

The spelling of 684985 in words is "six hundred eighty-four thousand, nine hundred eighty-five".