18113209 has 2 divisors, whose sum is σ = 18113210. Its totient is φ = 18113208.

The previous prime is 18113203. The next prime is 18113231. The reversal of 18113209 is 90231181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15642025 + 2471184 = 3955^2 + 1572^2 .

It is a cyclic number.

It is not a de Polignac number, because 18113209 - 2¹⁵ = 18080441 is a prime.

It is equal to p_1158073 and since 18113209 and 1158073 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (18113203) 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, 9056604 + 9056605.

It is an arithmetic number, because the mean of its divisors is an integer number (9056605).

Almost surely, 2^18113209 is an apocalyptic number.

It is an amenable number.

18113209 is a deficient number, since it is larger than the sum of its proper divisors (1).

18113209 is an equidigital number, since it uses as much as digits as its factorization.

18113209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 18113209 is about 4255.9615834732. The cubic root of 18113209 is about 262.6224202987.

The spelling of 18113209 in words is "eighteen million, one hundred thirteen thousand, two hundred nine".