18198889 has 2 divisors, whose sum is σ = 18198890. Its totient is φ = 18198888.

The previous prime is 18198841. The next prime is 18198893. The reversal of 18198889 is 98889181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15366400 + 2832489 = 3920^2 + 1683^2 .

It is a cyclic number.

It is not a de Polignac number, because 18198889 - 2¹⁷ = 18067817 is a prime.

It is not a weakly prime, because it can be changed into another prime (18198839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9099444 + 9099445.

It is an arithmetic number, because the mean of its divisors is an integer number (9099445).

Almost surely, 2^18198889 is an apocalyptic number.

It is an amenable number.

18198889 is a deficient number, since it is larger than the sum of its proper divisors (1).

18198889 is an equidigital number, since it uses as much as digits as its factorization.

18198889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 331776, while the sum is 52.

The square root of 18198889 is about 4266.0155883447. The cubic root of 18198889 is about 263.0358589609.

The spelling of 18198889 in words is "eighteen million, one hundred ninety-eight thousand, eight hundred eighty-nine".