684955889 has 2 divisors, whose sum is σ = 684955890. Its totient is φ = 684955888.

The previous prime is 684955883. The next prime is 684955903. The reversal of 684955889 is 988559486.

684955889 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., 596971489 + 87984400 = 24433^2 + 9380^2 .

It is a cyclic number.

It is not a de Polignac number, because 684955889 - 2¹² = 684951793 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (684955883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342477944 + 342477945.

It is an arithmetic number, because the mean of its divisors is an integer number (342477945).

Almost surely, 2^684955889 is an apocalyptic number.

It is an amenable number.

684955889 is a deficient number, since it is larger than the sum of its proper divisors (1).

684955889 is an equidigital number, since it uses as much as digits as its factorization.

684955889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24883200, while the sum is 62.

The square root of 684955889 is about 26171.6619457000. The cubic root of 684955889 is about 881.4970596203.

The spelling of 684955889 in words is "six hundred eighty-four million, nine hundred fifty-five thousand, eight hundred eighty-nine".