18281489 has 2 divisors, whose sum is σ = 18281490. Its totient is φ = 18281488.

The previous prime is 18281447. The next prime is 18281519. The reversal of 18281489 is 98418281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16265089 + 2016400 = 4033^2 + 1420^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18281489 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18281089) 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, 9140744 + 9140745.

It is an arithmetic number, because the mean of its divisors is an integer number (9140745).

Almost surely, 2^18281489 is an apocalyptic number.

It is an amenable number.

18281489 is a deficient number, since it is larger than the sum of its proper divisors (1).

18281489 is an equidigital number, since it uses as much as digits as its factorization.

18281489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36864, while the sum is 41.

The square root of 18281489 is about 4275.6857929460. The cubic root of 18281489 is about 263.4332087458.

The spelling of 18281489 in words is "eighteen million, two hundred eighty-one thousand, four hundred eighty-nine".