684706618369 has 2 divisors, whose sum is σ = 684706618370. Its totient is φ = 684706618368.

The previous prime is 684706618327. The next prime is 684706618403. The reversal of 684706618369 is 963816607486.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 414864810000 + 269841808369 = 644100^2 + 519463^2 .

It is a cyclic number.

It is not a de Polignac number, because 684706618369 - 2⁹ = 684706617857 is a prime.

It is a super-2 number, since 2×684706618369² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 684706618369.

It is not a weakly prime, because it can be changed into another prime (684706618319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342353309184 + 342353309185.

It is an arithmetic number, because the mean of its divisors is an integer number (342353309185).

Almost surely, 2^684706618369 is an apocalyptic number.

It is an amenable number.

684706618369 is a deficient number, since it is larger than the sum of its proper divisors (1).

684706618369 is an equidigital number, since it uses as much as digits as its factorization.

684706618369 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62705664, while the sum is 64.

The spelling of 684706618369 in words is "six hundred eighty-four billion, seven hundred six million, six hundred eighteen thousand, three hundred sixty-nine".