18922889 has 2 divisors, whose sum is σ = 18922890. Its totient is φ = 18922888.

The previous prime is 18922861. The next prime is 18922901. The reversal of 18922889 is 98822981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12369289 + 6553600 = 3517^2 + 2560^2 .

It is a cyclic number.

It is not a de Polignac number, because 18922889 - 2¹² = 18918793 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 (18922289) 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, 9461444 + 9461445.

It is an arithmetic number, because the mean of its divisors is an integer number (9461445).

Almost surely, 2^18922889 is an apocalyptic number.

It is an amenable number.

18922889 is a deficient number, since it is larger than the sum of its proper divisors (1).

18922889 is an equidigital number, since it uses as much as digits as its factorization.

18922889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 165888, while the sum is 47.

The square root of 18922889 is about 4350.0447124139. The cubic root of 18922889 is about 266.4786874858.

The spelling of 18922889 in words is "eighteen million, nine hundred twenty-two thousand, eight hundred eighty-nine".