18808992409 has 4 divisors (see below), whose sum is σ = 18810892900. Its totient is φ = 18807091920.

The previous prime is 18808992403. The next prime is 18808992451. The reversal of 18808992409 is 90429980881.

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 5165584384 + 13643408025 = 71872^2 + 116805^2 .

It is a cyclic number.

It is not a de Polignac number, because 18808992409 - 2³ = 18808992401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18808992401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 935322 + ... + 955219.

It is an arithmetic number, because the mean of its divisors is an integer number (4702723225).

Almost surely, 2^18808992409 is an apocalyptic number.

It is an amenable number.

18808992409 is a deficient number, since it is larger than the sum of its proper divisors (1900491).

18808992409 is an equidigital number, since it uses as much as digits as its factorization.

18808992409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1900490.

The product of its (nonzero) digits is 2985984, while the sum is 58.

The spelling of 18808992409 in words is "eighteen billion, eight hundred eight million, nine hundred ninety-two thousand, four hundred nine".