18459809 has 2 divisors, whose sum is σ = 18459810. Its totient is φ = 18459808.

The previous prime is 18459797. The next prime is 18459817. The reversal of 18459809 is 90895481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16224784 + 2235025 = 4028^2 + 1495^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18459809 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18459809.

It is not a weakly prime, because it can be changed into another prime (18459829) 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, 9229904 + 9229905.

It is an arithmetic number, because the mean of its divisors is an integer number (9229905).

Almost surely, 2^18459809 is an apocalyptic number.

It is an amenable number.

18459809 is a deficient number, since it is larger than the sum of its proper divisors (1).

18459809 is an equidigital number, since it uses as much as digits as its factorization.

18459809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 103680, while the sum is 44.

The square root of 18459809 is about 4296.4879843891. The cubic root of 18459809 is about 264.2869593597.

The spelling of 18459809 in words is "eighteen million, four hundred fifty-nine thousand, eight hundred nine".