18404189 has 2 divisors, whose sum is σ = 18404190. Its totient is φ = 18404188.

The previous prime is 18404161. The next prime is 18404201. The reversal of 18404189 is 98140481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17081689 + 1322500 = 4133^2 + 1150^2 .

It is an emirp because it is prime and its reverse (98140481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18404189 - 2¹² = 18400093 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18404689) 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, 9202094 + 9202095.

It is an arithmetic number, because the mean of its divisors is an integer number (9202095).

Almost surely, 2^18404189 is an apocalyptic number.

It is an amenable number.

18404189 is a deficient number, since it is larger than the sum of its proper divisors (1).

18404189 is an equidigital number, since it uses as much as digits as its factorization.

18404189 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 35.

The square root of 18404189 is about 4290.0103729478. The cubic root of 18404189 is about 264.0212572797.

The spelling of 18404189 in words is "eighteen million, four hundred four thousand, one hundred eighty-nine".