18023909 has 2 divisors, whose sum is σ = 18023910. Its totient is φ = 18023908.

The previous prime is 18023849. The next prime is 18023911. The reversal of 18023909 is 90932081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10099684 + 7924225 = 3178^2 + 2815^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18023909 is a prime.

It is a super-2 number, since 2×18023909² = 649722591280562, which contains 22 as substring.

Together with 18023911, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18023959) 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, 9011954 + 9011955.

It is an arithmetic number, because the mean of its divisors is an integer number (9011955).

Almost surely, 2^18023909 is an apocalyptic number.

It is an amenable number.

18023909 is a deficient number, since it is larger than the sum of its proper divisors (1).

18023909 is an equidigital number, since it uses as much as digits as its factorization.

18023909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 18023909 is about 4245.4574547391. The cubic root of 18023909 is about 262.1901238347.

The spelling of 18023909 in words is "eighteen million, twenty-three thousand, nine hundred nine".