684889 has 2 divisors, whose sum is σ = 684890. Its totient is φ = 684888.

The previous prime is 684869. The next prime is 684923. The reversal of 684889 is 988486.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 648025 + 36864 = 805^2 + 192^2 .

It is a cyclic number.

It is not a de Polignac number, because 684889 - 2⁵ = 684857 is a prime.

684889 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (684809) 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 as a sum of consecutive naturals, namely, 342444 + 342445.

It is an arithmetic number, because the mean of its divisors is an integer number (342445).

2⁶⁸⁴⁸⁸⁹ is an apocalyptic number.

It is an amenable number.

684889 is a deficient number, since it is larger than the sum of its proper divisors (1).

684889 is an equidigital number, since it uses as much as digits as its factorization.

684889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 110592, while the sum is 43.

The square root of 684889 is about 827.5802075932. The cubic root of 684889 is about 88.1468364645.

The spelling of 684889 in words is "six hundred eighty-four thousand, eight hundred eighty-nine".