1989340809 has 4 divisors (see below), whose sum is σ = 2652454416. Its totient is φ = 1326227204.

The previous prime is 1989340807. The next prime is 1989340813. The reversal of 1989340809 is 9080439891.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1989340809 - 2¹ = 1989340807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1989340807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 331556799 + ... + 331556804.

It is an arithmetic number, because the mean of its divisors is an integer number (663113604).

Almost surely, 2^1989340809 is an apocalyptic number.

It is an amenable number.

1989340809 is a deficient number, since it is larger than the sum of its proper divisors (663113607).

1989340809 is an equidigital number, since it uses as much as digits as its factorization.

1989340809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 663113606.

The product of its (nonzero) digits is 559872, while the sum is 51.

The square root of 1989340809 is about 44602.0269606663. The cubic root of 1989340809 is about 1257.6787718334.

The spelling of 1989340809 in words is "one billion, nine hundred eighty-nine million, three hundred forty thousand, eight hundred nine".