18839020891 has 2 divisors, whose sum is σ = 18839020892. Its totient is φ = 18839020890.

The previous prime is 18839020873. The next prime is 18839020909. The reversal of 18839020891 is 19802093881.

It is a balanced prime because it is at equal distance from previous prime (18839020873) and next prime (18839020909).

It is an emirp because it is prime and its reverse (19802093881) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18839020891 - 2²⁹ = 18302149979 is a prime.

It is not a weakly prime, because it can be changed into another prime (18839020801) 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, 9419510445 + 9419510446.

It is an arithmetic number, because the mean of its divisors is an integer number (9419510446).

Almost surely, 2^18839020891 is an apocalyptic number.

18839020891 is a deficient number, since it is larger than the sum of its proper divisors (1).

18839020891 is an equidigital number, since it uses as much as digits as its factorization.

18839020891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 248832, while the sum is 49.

The spelling of 18839020891 in words is "eighteen billion, eight hundred thirty-nine million, twenty thousand, eight hundred ninety-one".