684686 has 4 divisors (see below), whose sum is σ = 1027032. Its totient is φ = 342342.

The previous prime is 684683. The next prime is 684713. The reversal of 684686 is 686486.

684686 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 686486 = 2 ⋅343243.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 684686.

It is not an unprimeable number, because it can be changed into a prime (684683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171170 + ... + 171173.

It is an arithmetic number, because the mean of its divisors is an integer number (256758).

2⁶⁸⁴⁶⁸⁶ is an apocalyptic number.

684686 is a deficient number, since it is larger than the sum of its proper divisors (342346).

684686 is a wasteful number, since it uses less digits than its factorization.

684686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342345.

The product of its digits is 55296, while the sum is 38.

The square root of 684686 is about 827.4575517814. The cubic root of 684686 is about 88.1381267437.

The spelling of 684686 in words is "six hundred eighty-four thousand, six hundred eighty-six".