17955840809 has 4 divisors (see below), whose sum is σ = 17991118020. Its totient is φ = 17920563600.

The previous prime is 17955840757. The next prime is 17955840811. The reversal of 17955840809 is 90804855971.

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 5293290025 + 12662550784 = 72755^2 + 112528^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17955840809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (17955840839) 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 in 3 ways as a sum of consecutive naturals, for example, 17637842 + ... + 17638859.

It is an arithmetic number, because the mean of its divisors is an integer number (4497779505).

Almost surely, 2^17955840809 is an apocalyptic number.

It is an amenable number.

17955840809 is a deficient number, since it is larger than the sum of its proper divisors (35277211).

17955840809 is an equidigital number, since it uses as much as digits as its factorization.

17955840809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35277210.

The product of its (nonzero) digits is 3628800, while the sum is 56.

The spelling of 17955840809 in words is "seventeen billion, nine hundred fifty-five million, eight hundred forty thousand, eight hundred nine".