18368518409 has 2 divisors, whose sum is σ = 18368518410. Its totient is φ = 18368518408.

The previous prime is 18368518361. The next prime is 18368518463. The reversal of 18368518409 is 90481586381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15079840000 + 3288678409 = 122800^2 + 57347^2 .

It is a cyclic number.

It is not a de Polignac number, because 18368518409 - 2³² = 14073551113 is a prime.

It is not a weakly prime, because it can be changed into another prime (18368518499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9184259204 + 9184259205.

It is an arithmetic number, because the mean of its divisors is an integer number (9184259205).

Almost surely, 2^18368518409 is an apocalyptic number.

It is an amenable number.

18368518409 is a deficient number, since it is larger than the sum of its proper divisors (1).

18368518409 is an equidigital number, since it uses as much as digits as its factorization.

18368518409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1658880, while the sum is 53.

The spelling of 18368518409 in words is "eighteen billion, three hundred sixty-eight million, five hundred eighteen thousand, four hundred nine".