18805379909 has 2 divisors, whose sum is σ = 18805379910. Its totient is φ = 18805379908.

The previous prime is 18805379881. The next prime is 18805379911. The reversal of 18805379909 is 90997350881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14531097025 + 4274282884 = 120545^2 + 65378^2 .

It is an emirp because it is prime and its reverse (90997350881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18805379909 - 2⁸ = 18805379653 is a prime.

Together with 18805379911, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18805372909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9402689954 + 9402689955.

It is an arithmetic number, because the mean of its divisors is an integer number (9402689955).

Almost surely, 2^18805379909 is an apocalyptic number.

It is an amenable number.

18805379909 is a deficient number, since it is larger than the sum of its proper divisors (1).

18805379909 is an equidigital number, since it uses as much as digits as its factorization.

18805379909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4898880, while the sum is 59.

The spelling of 18805379909 in words is "eighteen billion, eight hundred five million, three hundred seventy-nine thousand, nine hundred nine".