18363877691 has 2 divisors, whose sum is σ = 18363877692. Its totient is φ = 18363877690.

The previous prime is 18363877687. The next prime is 18363877747. The reversal of 18363877691 is 19677836381.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18363877691 - 2² = 18363877687 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18363877691.

It is not a weakly prime, because it can be changed into another prime (18363877601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9181938845 + 9181938846.

It is an arithmetic number, because the mean of its divisors is an integer number (9181938846).

Almost surely, 2^18363877691 is an apocalyptic number.

18363877691 is a deficient number, since it is larger than the sum of its proper divisors (1).

18363877691 is an equidigital number, since it uses as much as digits as its factorization.

18363877691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9144576, while the sum is 59.

The spelling of 18363877691 in words is "eighteen billion, three hundred sixty-three million, eight hundred seventy-seven thousand, six hundred ninety-one".