684406510729 has 2 divisors, whose sum is σ = 684406510730. Its totient is φ = 684406510728.

The previous prime is 684406510717. The next prime is 684406510793. The reversal of 684406510729 is 927015604486.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 517317685504 + 167088825225 = 719248^2 + 408765^2 .

It is a cyclic number.

It is not a de Polignac number, because 684406510729 - 2²⁵ = 684372956297 is a prime.

It is a super-2 number, since 2×684406510729² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (684406510429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342203255364 + 342203255365.

It is an arithmetic number, because the mean of its divisors is an integer number (342203255365).

Almost surely, 2^684406510729 is an apocalyptic number.

It is an amenable number.

684406510729 is a deficient number, since it is larger than the sum of its proper divisors (1).

684406510729 is an equidigital number, since it uses as much as digits as its factorization.

684406510729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2903040, while the sum is 52.

The spelling of 684406510729 in words is "six hundred eighty-four billion, four hundred six million, five hundred ten thousand, seven hundred twenty-nine".