18399615697 has 2 divisors, whose sum is σ = 18399615698. Its totient is φ = 18399615696.

The previous prime is 18399615691. The next prime is 18399615701. The reversal of 18399615697 is 79651699381.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13458088081 + 4941527616 = 116009^2 + 70296^2 .

It is an emirp because it is prime and its reverse (79651699381) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18399615697 - 2¹¹ = 18399613649 is a prime.

It is not a weakly prime, because it can be changed into another prime (18399615691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9199807848 + 9199807849.

It is an arithmetic number, because the mean of its divisors is an integer number (9199807849).

Almost surely, 2^18399615697 is an apocalyptic number.

It is an amenable number.

18399615697 is a deficient number, since it is larger than the sum of its proper divisors (1).

18399615697 is an equidigital number, since it uses as much as digits as its factorization.

18399615697 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22044960, while the sum is 64.

The spelling of 18399615697 in words is "eighteen billion, three hundred ninety-nine million, six hundred fifteen thousand, six hundred ninety-seven".