684881 has 4 divisors (see below), whose sum is σ = 691764. Its totient is φ = 678000.

The previous prime is 684869. The next prime is 684889. The reversal of 684881 is 188486.

684881 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.

It can be written as a sum of positive squares in 2 ways, for example, as 512656 + 172225 = 716^2 + 415^2 .

It is a cyclic number.

It is not a de Polignac number, because 684881 - 2¹⁰ = 683857 is a prime.

It is a super-2 number, since 2×684881² = 938123968322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (684889) 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, 3290 + ... + 3491.

It is an arithmetic number, because the mean of its divisors is an integer number (172941).

2⁶⁸⁴⁸⁸¹ is an apocalyptic number.

It is an amenable number.

684881 is a deficient number, since it is larger than the sum of its proper divisors (6883).

684881 is a wasteful number, since it uses less digits than its factorization.

684881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6882.

The product of its digits is 12288, while the sum is 35.

The square root of 684881 is about 827.5753742107. The cubic root of 684881 is about 88.1464932569.

The spelling of 684881 in words is "six hundred eighty-four thousand, eight hundred eighty-one".