18519039809 has 4 divisors (see below), whose sum is σ = 18698836416. Its totient is φ = 18339243204.

The previous prime is 18519039769. The next prime is 18519039841. The reversal of 18519039809 is 90893091581.

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 18519039809 - 2¹⁶ = 18518974273 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18519039899) 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, 89898149 + ... + 89898354.

It is an arithmetic number, because the mean of its divisors is an integer number (4674709104).

Almost surely, 2^18519039809 is an apocalyptic number.

It is an amenable number.

18519039809 is a deficient number, since it is larger than the sum of its proper divisors (179796607).

18519039809 is a wasteful number, since it uses less digits than its factorization.

18519039809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179796606.

The product of its (nonzero) digits is 699840, while the sum is 53.

The spelling of 18519039809 in words is "eighteen billion, five hundred nineteen million, thirty-nine thousand, eight hundred nine".