18242209 has 2 divisors, whose sum is σ = 18242210. Its totient is φ = 18242208.

The previous prime is 18242183. The next prime is 18242249. The reversal of 18242209 is 90224281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18190225 + 51984 = 4265^2 + 228^2 .

It is a cyclic number.

It is not a de Polignac number, because 18242209 - 2¹¹ = 18240161 is a prime.

It is not a weakly prime, because it can be changed into another prime (18242249) 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, 9121104 + 9121105.

It is an arithmetic number, because the mean of its divisors is an integer number (9121105).

Almost surely, 2^18242209 is an apocalyptic number.

It is an amenable number.

18242209 is a deficient number, since it is larger than the sum of its proper divisors (1).

18242209 is an equidigital number, since it uses as much as digits as its factorization.

18242209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 18242209 is about 4271.0899077402. The cubic root of 18242209 is about 263.2444007050.

The spelling of 18242209 in words is "eighteen million, two hundred forty-two thousand, two hundred nine".