6405439009 has 4 divisors (see below), whose sum is σ = 6405812100. Its totient is φ = 6405065920.

The previous prime is 6405438997. The next prime is 6405439091. The reversal of 6405439009 is 9009345046.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3499905600 + 2905533409 = 59160^2 + 53903^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6405439009 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6405439109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159484 + ... + 195565.

It is an arithmetic number, because the mean of its divisors is an integer number (1601453025).

Almost surely, 2^6405439009 is an apocalyptic number.

It is an amenable number.

6405439009 is a deficient number, since it is larger than the sum of its proper divisors (373091).

6405439009 is a wasteful number, since it uses less digits than its factorization.

6405439009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373090.

The product of its (nonzero) digits is 116640, while the sum is 40.

The square root of 6405439009 is about 80033.9865869494. The cubic root of 6405439009 is about 1857.1613354281.

The spelling of 6405439009 in words is "six billion, four hundred five million, four hundred thirty-nine thousand, nine".