3989809 has 2 divisors, whose sum is σ = 3989810. Its totient is φ = 3989808.

The previous prime is 3989807. The next prime is 3989831. The reversal of 3989809 is 9089893.

3989809 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., 3045025 + 944784 = 1745^2 + 972^2 .

It is an emirp because it is prime and its reverse (9089893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3989809 - 2¹ = 3989807 is a prime.

Together with 3989807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (3989801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1994904 + 1994905.

It is an arithmetic number, because the mean of its divisors is an integer number (1994905).

Almost surely, 2^3989809 is an apocalyptic number.

It is an amenable number.

3989809 is a deficient number, since it is larger than the sum of its proper divisors (1).

3989809 is an equidigital number, since it uses as much as digits as its factorization.

3989809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 46.

The square root of 3989809 is about 1997.4506251720. The cubic root of 3989809 is about 158.6051805127.

The spelling of 3989809 in words is "three million, nine hundred eighty-nine thousand, eight hundred nine".