684161 has 4 divisors (see below), whose sum is σ = 685824. Its totient is φ = 682500.

The previous prime is 684157. The next prime is 684163. The reversal of 684161 is 161486.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 684161 - 2² = 684157 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 684161.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 684161.

It is not an unprimeable number, because it can be changed into a prime (684163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 296 + ... + 1206.

It is an arithmetic number, because the mean of its divisors is an integer number (171456).

2⁶⁸⁴¹⁶¹ is an apocalyptic number.

It is an amenable number.

684161 is a deficient number, since it is larger than the sum of its proper divisors (1663).

684161 is an equidigital number, since it uses as much as digits as its factorization.

684161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1662.

The product of its digits is 1152, while the sum is 26.

The square root of 684161 is about 827.1402541286. The cubic root of 684161 is about 88.1155936173.

The spelling of 684161 in words is "six hundred eighty-four thousand, one hundred sixty-one".