18443845009 has 2 divisors, whose sum is σ = 18443845010. Its totient is φ = 18443845008.

The previous prime is 18443844973. The next prime is 18443845051. The reversal of 18443845009 is 90054834481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10827443025 + 7616401984 = 104055^2 + 87272^2 .

It is an emirp because it is prime and its reverse (90054834481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18443845009 - 2²⁹ = 17906974097 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18443845009.

It is not a weakly prime, because it can be changed into another prime (18443845709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9221922504 + 9221922505.

It is an arithmetic number, because the mean of its divisors is an integer number (9221922505).

Almost surely, 2^18443845009 is an apocalyptic number.

It is an amenable number.

18443845009 is a deficient number, since it is larger than the sum of its proper divisors (1).

18443845009 is an equidigital number, since it uses as much as digits as its factorization.

18443845009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 552960, while the sum is 46.

The spelling of 18443845009 in words is "eighteen billion, four hundred forty-three million, eight hundred forty-five thousand, nine".