18243564517 has 2 divisors, whose sum is σ = 18243564518. Its totient is φ = 18243564516.

The previous prime is 18243564491. The next prime is 18243564529. The reversal of 18243564517 is 71546534281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18140318596 + 103245921 = 134686^2 + 10161^2 .

It is a cyclic number.

It is not a de Polignac number, because 18243564517 - 2⁷ = 18243564389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18243564587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9121782258 + 9121782259.

It is an arithmetic number, because the mean of its divisors is an integer number (9121782259).

Almost surely, 2^18243564517 is an apocalyptic number.

It is an amenable number.

18243564517 is a deficient number, since it is larger than the sum of its proper divisors (1).

18243564517 is an equidigital number, since it uses as much as digits as its factorization.

18243564517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 806400, while the sum is 46.

The spelling of 18243564517 in words is "eighteen billion, two hundred forty-three million, five hundred sixty-four thousand, five hundred seventeen".