18489257 has 2 divisors, whose sum is σ = 18489258. Its totient is φ = 18489256.

The previous prime is 18489241. The next prime is 18489259. The reversal of 18489257 is 75298481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16736281 + 1752976 = 4091^2 + 1324^2 .

It is a cyclic number.

It is not a de Polignac number, because 18489257 - 2⁴ = 18489241 is a prime.

Together with 18489259, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18489259) 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, 9244628 + 9244629.

It is an arithmetic number, because the mean of its divisors is an integer number (9244629).

Almost surely, 2^18489257 is an apocalyptic number.

It is an amenable number.

18489257 is a deficient number, since it is larger than the sum of its proper divisors (1).

18489257 is an equidigital number, since it uses as much as digits as its factorization.

18489257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 161280, while the sum is 44.

The square root of 18489257 is about 4299.9136037832. The cubic root of 18489257 is about 264.4274192381.

The spelling of 18489257 in words is "eighteen million, four hundred eighty-nine thousand, two hundred fifty-seven".