18208189 has 2 divisors, whose sum is σ = 18208190. Its totient is φ = 18208188.

The previous prime is 18208159. The next prime is 18208231. The reversal of 18208189 is 98180281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18207289 + 900 = 4267^2 + 30^2 .

It is a cyclic number.

It is not a de Polignac number, because 18208189 - 2¹⁹ = 17683901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18208159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9104094 + 9104095.

It is an arithmetic number, because the mean of its divisors is an integer number (9104095).

Almost surely, 2^18208189 is an apocalyptic number.

It is an amenable number.

18208189 is a deficient number, since it is larger than the sum of its proper divisors (1).

18208189 is an equidigital number, since it uses as much as digits as its factorization.

18208189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9216, while the sum is 37.

The square root of 18208189 is about 4267.1054592077. The cubic root of 18208189 is about 263.0806568772.

The spelling of 18208189 in words is "eighteen million, two hundred eight thousand, one hundred eighty-nine".