985666789 has 2 divisors, whose sum is σ = 985666790. Its totient is φ = 985666788.

The previous prime is 985666763. The next prime is 985666807. The reversal of 985666789 is 987666589.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 575280225 + 410386564 = 23985^2 + 20258^2 .

It is a cyclic number.

It is not a de Polignac number, because 985666789 - 2⁵ = 985666757 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 985666789.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (985666889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 492833394 + 492833395.

It is an arithmetic number, because the mean of its divisors is an integer number (492833395).

Almost surely, 2^985666789 is an apocalyptic number.

It is an amenable number.

985666789 is a deficient number, since it is larger than the sum of its proper divisors (1).

985666789 is an equidigital number, since it uses as much as digits as its factorization.

985666789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39191040, while the sum is 64.

The square root of 985666789 is about 31395.3306878587. The cubic root of 985666789 is about 995.1992527066.

The spelling of 985666789 in words is "nine hundred eighty-five million, six hundred sixty-six thousand, seven hundred eighty-nine".