18000989 has 2 divisors, whose sum is σ = 18000990. Its totient is φ = 18000988.

The previous prime is 18000971. The next prime is 18001031. The reversal of 18000989 is 98900081.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17556100 + 444889 = 4190^2 + 667^2 .

It is a cyclic number.

It is not a de Polignac number, because 18000989 - 2¹² = 17996893 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18000919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9000494 + 9000495.

It is an arithmetic number, because the mean of its divisors is an integer number (9000495).

Almost surely, 2^18000989 is an apocalyptic number.

It is an amenable number.

18000989 is a deficient number, since it is larger than the sum of its proper divisors (1).

18000989 is an equidigital number, since it uses as much as digits as its factorization.

18000989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 35.

The square root of 18000989 is about 4242.7572402861. The cubic root of 18000989 is about 262.0789391723.

The spelling of 18000989 in words is "eighteen million, nine hundred eighty-nine", and thus it is an aban number.