684001 has 4 divisors (see below), whose sum is σ = 699952. Its totient is φ = 668052.

The previous prime is 683983. The next prime is 684007. The reversal of 684001 is 100486.

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 684001 - 2⁷ = 683873 is a prime.

It is a Duffinian number.

684001 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 684001.

It is not an unprimeable number, because it can be changed into a prime (684007) 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, 7911 + ... + 7996.

It is an arithmetic number, because the mean of its divisors is an integer number (174988).

2⁶⁸⁴⁰⁰¹ is an apocalyptic number.

It is an amenable number.

684001 is a deficient number, since it is larger than the sum of its proper divisors (15951).

684001 is a wasteful number, since it uses less digits than its factorization.

684001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15950.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 684001 is about 827.0435296887. The cubic root of 684001 is about 88.1087240870.

Adding to 684001 its reverse (100486), we get a palindrome (784487).

The spelling of 684001 in words is "six hundred eighty-four thousand, one".