18006389 has 2 divisors, whose sum is σ = 18006390. Its totient is φ = 18006388.

The previous prime is 18006377. The next prime is 18006413. The reversal of 18006389 is 98360081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14554225 + 3452164 = 3815^2 + 1858^2 .

It is an emirp because it is prime and its reverse (98360081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18006389 - 2¹² = 18002293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18002389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9003194 + 9003195.

It is an arithmetic number, because the mean of its divisors is an integer number (9003195).

Almost surely, 2^18006389 is an apocalyptic number.

It is an amenable number.

18006389 is a deficient number, since it is larger than the sum of its proper divisors (1).

18006389 is an equidigital number, since it uses as much as digits as its factorization.

18006389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 18006389 is about 4243.3935711880. The cubic root of 18006389 is about 262.1051430063.

The spelling of 18006389 in words is "eighteen million, six thousand, three hundred eighty-nine".