684321 has 16 divisors (see below), whose sum is σ = 1010880. Its totient is φ = 408320.

The previous prime is 684311. The next prime is 684329. The reversal of 684321 is 123486.

It is a happy number.

It is not a de Polignac number, because 684321 - 2⁵ = 684289 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 684291 and 684300.

It is not an unprimeable number, because it can be changed into a prime (684329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2821 + ... + 3053.

It is an arithmetic number, because the mean of its divisors is an integer number (63180).

2⁶⁸⁴³²¹ is an apocalyptic number.

It is an amenable number.

684321 is a deficient number, since it is larger than the sum of its proper divisors (326559).

684321 is a wasteful number, since it uses less digits than its factorization.

684321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336.

The product of its digits is 1152, while the sum is 24.

The square root of 684321 is about 827.2369672591. The cubic root of 684321 is about 88.1224620767.

The spelling of 684321 in words is "six hundred eighty-four thousand, three hundred twenty-one".