18298309 has 2 divisors, whose sum is σ = 18298310. Its totient is φ = 18298308.

The previous prime is 18298297. The next prime is 18298327. The reversal of 18298309 is 90389281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16785409 + 1512900 = 4097^2 + 1230^2 .

It is an emirp because it is prime and its reverse (90389281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18298309 - 2²³ = 9909701 is a prime.

It is a super-2 number, since 2×18298309² = 669656224518962, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18298009) 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, 9149154 + 9149155.

It is an arithmetic number, because the mean of its divisors is an integer number (9149155).

Almost surely, 2^18298309 is an apocalyptic number.

It is an amenable number.

18298309 is a deficient number, since it is larger than the sum of its proper divisors (1).

18298309 is an equidigital number, since it uses as much as digits as its factorization.

18298309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 18298309 is about 4277.6522766583. The cubic root of 18298309 is about 263.5139751130.

The spelling of 18298309 in words is "eighteen million, two hundred ninety-eight thousand, three hundred nine".