684401 has 4 divisors (see below), whose sum is σ = 686400. Its totient is φ = 682404.

The previous prime is 684379. The next prime is 684407. The reversal of 684401 is 104486.

It is a happy number.

684401 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 684401 - 2⁶ = 684337 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684407) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 341 + ... + 1218.

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

2⁶⁸⁴⁴⁰¹ is an apocalyptic number.

It is an amenable number.

684401 is a deficient number, since it is larger than the sum of its proper divisors (1999).

684401 is a wasteful number, since it uses less digits than its factorization.

684401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1998.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 684401 is about 827.2853195845. The cubic root of 684401 is about 88.1258959049.

Adding to 684401 its reverse (104486), we get a palindrome (788887).

The spelling of 684401 in words is "six hundred eighty-four thousand, four hundred one".