684491 has 4 divisors (see below), whose sum is σ = 686400. Its totient is φ = 682584.

The previous prime is 684473. The next prime is 684493. The reversal of 684491 is 194486.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 684491 - 2⁶ = 684427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (684493) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 236 + ... + 1193.

It is an arithmetic number, because the mean of its divisors is an integer number (171600).

2⁶⁸⁴⁴⁹¹ is an apocalyptic number.

684491 is a deficient number, since it is larger than the sum of its proper divisors (1909).

684491 is a wasteful number, since it uses less digits than its factorization.

684491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1908.

The product of its digits is 6912, while the sum is 32.

The square root of 684491 is about 827.3397125728. The cubic root of 684491 is about 88.1297586418.

The spelling of 684491 in words is "six hundred eighty-four thousand, four hundred ninety-one".