1684321 has 4 divisors (see below), whose sum is σ = 1725444. Its totient is φ = 1643200.

The previous prime is 1684307. The next prime is 1684327. The reversal of 1684321 is 1234861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1234861 = 109 ⋅11329.

It can be written as a sum of positive squares in 2 ways, for example, as 336400 + 1347921 = 580^2 + 1161^2 .

It is a cyclic number.

It is not a de Polignac number, because 1684321 - 2⁵ = 1684289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1684327) 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, 20500 + ... + 20581.

It is an arithmetic number, because the mean of its divisors is an integer number (431361).

2^1684321 is an apocalyptic number.

It is an amenable number.

1684321 is a deficient number, since it is larger than the sum of its proper divisors (41123).

1684321 is an equidigital number, since it uses as much as digits as its factorization.

1684321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41122.

The product of its digits is 1152, while the sum is 25.

The square root of 1684321 is about 1297.8139311935. The cubic root of 1684321 is about 118.9802711921.

It can be divided in two parts, 168 and 4321, that added together give a square (4489 = 67²).

The spelling of 1684321 in words is "one million, six hundred eighty-four thousand, three hundred twenty-one".