138018815989 has 2 divisors, whose sum is σ = 138018815990. Its totient is φ = 138018815988.

The previous prime is 138018815947. The next prime is 138018816029. The reversal of 138018815989 is 989518810831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 93045131089 + 44973684900 = 305033^2 + 212070^2 .

It is an emirp because it is prime and its reverse (989518810831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138018815989 - 2⁷ = 138018815861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138018815089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69009407994 + 69009407995.

It is an arithmetic number, because the mean of its divisors is an integer number (69009407995).

Almost surely, 2^138018815989 is an apocalyptic number.

It is an amenable number.

138018815989 is a deficient number, since it is larger than the sum of its proper divisors (1).

138018815989 is an equidigital number, since it uses as much as digits as its factorization.

138018815989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4976640, while the sum is 61.

The spelling of 138018815989 in words is "one hundred thirty-eight billion, eighteen million, eight hundred fifteen thousand, nine hundred eighty-nine".