1681578289 has 2 divisors, whose sum is σ = 1681578290. Its totient is φ = 1681578288.

The previous prime is 1681578221. The next prime is 1681578317. The reversal of 1681578289 is 9828751861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 923126689 + 758451600 = 30383^2 + 27540^2 .

It is an emirp because it is prime and its reverse (9828751861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1681578289 - 2⁷ = 1681578161 is a prime.

It is not a weakly prime, because it can be changed into another prime (1681578989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840789144 + 840789145.

It is an arithmetic number, because the mean of its divisors is an integer number (840789145).

Almost surely, 2^1681578289 is an apocalyptic number.

It is an amenable number.

1681578289 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681578289 is an equidigital number, since it uses as much as digits as its factorization.

1681578289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1935360, while the sum is 55.

The square root of 1681578289 is about 41007.0516984579. The cubic root of 1681578289 is about 1189.1565449341.

The spelling of 1681578289 in words is "one billion, six hundred eighty-one million, five hundred seventy-eight thousand, two hundred eighty-nine".