684605 has 8 divisors (see below), whose sum is σ = 826200. Its totient is φ = 544576.

The previous prime is 684599. The next prime is 684617. The reversal of 684605 is 506486.

It can be written as a sum of positive squares in 4 ways, for example, as 34969 + 649636 = 187^2 + 806^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 684605 - 2⁸ = 684349 is a prime.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1091 + ... + 1599.

It is an arithmetic number, because the mean of its divisors is an integer number (103275).

2⁶⁸⁴⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

684605 is a deficient number, since it is larger than the sum of its proper divisors (141595).

684605 is a wasteful number, since it uses less digits than its factorization.

684605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 783.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 684605 is about 827.4086052248. The cubic root of 684605 is about 88.1346509559.

The spelling of 684605 in words is "six hundred eighty-four thousand, six hundred five".