18539484209 has 2 divisors, whose sum is σ = 18539484210. Its totient is φ = 18539484208.

The previous prime is 18539484169. The next prime is 18539484241. The reversal of 18539484209 is 90248493581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12084165184 + 6455319025 = 109928^2 + 80345^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18539484209 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18539487209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9269742104 + 9269742105.

It is an arithmetic number, because the mean of its divisors is an integer number (9269742105).

Almost surely, 2^18539484209 is an apocalyptic number.

It is an amenable number.

18539484209 is a deficient number, since it is larger than the sum of its proper divisors (1).

18539484209 is an equidigital number, since it uses as much as digits as its factorization.

18539484209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2488320, while the sum is 53.

The spelling of 18539484209 in words is "eighteen billion, five hundred thirty-nine million, four hundred eighty-four thousand, two hundred nine".