18133889 has 2 divisors, whose sum is σ = 18133890. Its totient is φ = 18133888.

The previous prime is 18133877. The next prime is 18133891. The reversal of 18133889 is 98833181.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14554225 + 3579664 = 3815^2 + 1892^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18133889 is a prime.

It is a Sophie Germain prime.

Together with 18133891, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18133189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9066944 + 9066945.

It is an arithmetic number, because the mean of its divisors is an integer number (9066945).

Almost surely, 2^18133889 is an apocalyptic number.

It is an amenable number.

18133889 is a deficient number, since it is larger than the sum of its proper divisors (1).

18133889 is an equidigital number, since it uses as much as digits as its factorization.

18133889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 41.

The square root of 18133889 is about 4258.3904236225. The cubic root of 18133889 is about 262.7223283469.

The spelling of 18133889 in words is "eighteen million, one hundred thirty-three thousand, eight hundred eighty-nine".