18115309 has 2 divisors, whose sum is σ = 18115310. Its totient is φ = 18115308.

The previous prime is 18115297. The next prime is 18115313. The reversal of 18115309 is 90351181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11628100 + 6487209 = 3410^2 + 2547^2 .

It is an emirp because it is prime and its reverse (90351181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18115309 - 2⁵ = 18115277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18112309) 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, 9057654 + 9057655.

It is an arithmetic number, because the mean of its divisors is an integer number (9057655).

Almost surely, 2^18115309 is an apocalyptic number.

It is an amenable number.

18115309 is a deficient number, since it is larger than the sum of its proper divisors (1).

18115309 is an equidigital number, since it uses as much as digits as its factorization.

18115309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 28.

The square root of 18115309 is about 4256.2082890761. The cubic root of 18115309 is about 262.6325691679.

The spelling of 18115309 in words is "eighteen million, one hundred fifteen thousand, three hundred nine".