18388538717 has 2 divisors, whose sum is σ = 18388538718. Its totient is φ = 18388538716.

The previous prime is 18388538681. The next prime is 18388538761. The reversal of 18388538717 is 71783588381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17715343801 + 673194916 = 133099^2 + 25946^2 .

It is a cyclic number.

It is not a de Polignac number, because 18388538717 - 2¹² = 18388534621 is a prime.

It is a super-2 number, since 2×18388538717² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18388532717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9194269358 + 9194269359.

It is an arithmetic number, because the mean of its divisors is an integer number (9194269359).

Almost surely, 2^18388538717 is an apocalyptic number.

It is an amenable number.

18388538717 is a deficient number, since it is larger than the sum of its proper divisors (1).

18388538717 is an equidigital number, since it uses as much as digits as its factorization.

18388538717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9031680, while the sum is 59.

The spelling of 18388538717 in words is "eighteen billion, three hundred eighty-eight million, five hundred thirty-eight thousand, seven hundred seventeen".