18265238491 has 2 divisors, whose sum is σ = 18265238492. Its totient is φ = 18265238490.

The previous prime is 18265238399. The next prime is 18265238503. The reversal of 18265238491 is 19483256281.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18265238491 - 2⁹ = 18265237979 is a prime.

It is not a weakly prime, because it can be changed into another prime (18265208491) 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, 9132619245 + 9132619246.

It is an arithmetic number, because the mean of its divisors is an integer number (9132619246).

Almost surely, 2^18265238491 is an apocalyptic number.

18265238491 is a deficient number, since it is larger than the sum of its proper divisors (1).

18265238491 is an equidigital number, since it uses as much as digits as its factorization.

18265238491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 829440, while the sum is 49.

The spelling of 18265238491 in words is "eighteen billion, two hundred sixty-five million, two hundred thirty-eight thousand, four hundred ninety-one".