684866789 has 2 divisors, whose sum is σ = 684866790. Its totient is φ = 684866788.

The previous prime is 684866783. The next prime is 684866797. The reversal of 684866789 is 987668486.

It is a happy number.

684866789 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 443313025 + 241553764 = 21055^2 + 15542^2 .

It is a cyclic number.

It is not a de Polignac number, because 684866789 - 2⁴ = 684866773 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684866783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342433394 + 342433395.

It is an arithmetic number, because the mean of its divisors is an integer number (342433395).

Almost surely, 2^684866789 is an apocalyptic number.

It is an amenable number.

684866789 is a deficient number, since it is larger than the sum of its proper divisors (1).

684866789 is an equidigital number, since it uses as much as digits as its factorization.

684866789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27869184, while the sum is 62.

The square root of 684866789 is about 26169.9596675272. The cubic root of 684866789 is about 881.4588358479.

It can be divided in two parts, 6848 and 66789, that added together give a palindrome (73637).

The spelling of 684866789 in words is "six hundred eighty-four million, eight hundred sixty-six thousand, seven hundred eighty-nine".