18385516997 has 2 divisors, whose sum is σ = 18385516998. Its totient is φ = 18385516996.

The previous prime is 18385516993. The next prime is 18385517093. The reversal of 18385516997 is 79961558381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15285365956 + 3100151041 = 123634^2 + 55679^2 .

It is an emirp because it is prime and its reverse (79961558381) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18385516997 - 2² = 18385516993 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18385516993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9192758498 + 9192758499.

It is an arithmetic number, because the mean of its divisors is an integer number (9192758499).

Almost surely, 2^18385516997 is an apocalyptic number.

It is an amenable number.

18385516997 is a deficient number, since it is larger than the sum of its proper divisors (1).

18385516997 is an equidigital number, since it uses as much as digits as its factorization.

18385516997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16329600, while the sum is 62.

The spelling of 18385516997 in words is "eighteen billion, three hundred eighty-five million, five hundred sixteen thousand, nine hundred ninety-seven".