18843394993 has 2 divisors, whose sum is σ = 18843394994. Its totient is φ = 18843394992.

The previous prime is 18843394961. The next prime is 18843395009. The reversal of 18843394993 is 39949334881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15988843809 + 2854551184 = 126447^2 + 53428^2 .

It is a cyclic number.

It is not a de Polignac number, because 18843394993 - 2⁵ = 18843394961 is a prime.

It is not a weakly prime, because it can be changed into another prime (18843398993) 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, 9421697496 + 9421697497.

It is an arithmetic number, because the mean of its divisors is an integer number (9421697497).

Almost surely, 2^18843394993 is an apocalyptic number.

It is an amenable number.

18843394993 is a deficient number, since it is larger than the sum of its proper divisors (1).

18843394993 is an equidigital number, since it uses as much as digits as its factorization.

18843394993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20155392, while the sum is 61.

The spelling of 18843394993 in words is "eighteen billion, eight hundred forty-three million, three hundred ninety-four thousand, nine hundred ninety-three".