18459989 has 2 divisors, whose sum is σ = 18459990. Its totient is φ = 18459988.

The previous prime is 18459983. The next prime is 18459997. The reversal of 18459989 is 98995481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13764100 + 4695889 = 3710^2 + 2167^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18459989 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18459989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18459983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9229994 + 9229995.

It is an arithmetic number, because the mean of its divisors is an integer number (9229995).

Almost surely, 2^18459989 is an apocalyptic number.

It is an amenable number.

18459989 is a deficient number, since it is larger than the sum of its proper divisors (1).

18459989 is an equidigital number, since it uses as much as digits as its factorization.

18459989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 933120, while the sum is 53.

The square root of 18459989 is about 4296.5089316793. The cubic root of 18459989 is about 264.2878183700.

The spelling of 18459989 in words is "eighteen million, four hundred fifty-nine thousand, nine hundred eighty-nine".