684544813 has 2 divisors, whose sum is σ = 684544814. Its totient is φ = 684544812.

The previous prime is 684544781. The next prime is 684544843. The reversal of 684544813 is 318445486.

684544813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 344584969 + 339959844 = 18563^2 + 18438^2 .

It is a cyclic number.

It is not a de Polignac number, because 684544813 - 2⁵ = 684544781 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 684544813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684544843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342272406 + 342272407.

It is an arithmetic number, because the mean of its divisors is an integer number (342272407).

Almost surely, 2^684544813 is an apocalyptic number.

It is an amenable number.

684544813 is a deficient number, since it is larger than the sum of its proper divisors (1).

684544813 is an equidigital number, since it uses as much as digits as its factorization.

684544813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 368640, while the sum is 43.

The square root of 684544813 is about 26163.8073108636. The cubic root of 684544813 is about 881.3206809630.

The spelling of 684544813 in words is "six hundred eighty-four million, five hundred forty-four thousand, eight hundred thirteen".