18180689 has 2 divisors, whose sum is σ = 18180690. Its totient is φ = 18180688.

The previous prime is 18180677. The next prime is 18180697. The reversal of 18180689 is 98608181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10452289 + 7728400 = 3233^2 + 2780^2 .

It is a cyclic number.

It is not a de Polignac number, because 18180689 - 2⁸ = 18180433 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18180619) 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, 9090344 + 9090345.

It is an arithmetic number, because the mean of its divisors is an integer number (9090345).

Almost surely, 2^18180689 is an apocalyptic number.

It is an amenable number.

18180689 is a deficient number, since it is larger than the sum of its proper divisors (1).

18180689 is an equidigital number, since it uses as much as digits as its factorization.

18180689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27648, while the sum is 41.

The square root of 18180689 is about 4263.8819167514. The cubic root of 18180689 is about 262.9481457427.

The spelling of 18180689 in words is "eighteen million, one hundred eighty thousand, six hundred eighty-nine".