18000043499989 has 2 divisors, whose sum is σ = 18000043499990. Its totient is φ = 18000043499988.

The previous prime is 18000043499983. The next prime is 18000043500059. The reversal of 18000043499989 is 98999434000081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12369056879089 + 5630986620900 = 3516967^2 + 2372970^2 .

It is an emirp because it is prime and its reverse (98999434000081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18000043499989 - 2¹⁵ = 18000043467221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18000043499989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18000043499983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9000021749994 + 9000021749995.

It is an arithmetic number, because the mean of its divisors is an integer number (9000021749995).

Almost surely, 2^{18000043499989} is an apocalyptic number.

It is an amenable number.

18000043499989 is a deficient number, since it is larger than the sum of its proper divisors (1).

18000043499989 is an equidigital number, since it uses as much as digits as its factorization.

18000043499989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 20155392, while the sum is 64.

The spelling of 18000043499989 in words is "eighteen trillion, forty-three million, four hundred ninety-nine thousand, nine hundred eighty-nine".