18923189 has 2 divisors, whose sum is σ = 18923190. Its totient is φ = 18923188.

The previous prime is 18923153. The next prime is 18923197. The reversal of 18923189 is 98132981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18852964 + 70225 = 4342^2 + 265^2 .

It is a cyclic number.

It is not a de Polignac number, because 18923189 - 2²⁰ = 17874613 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 (18923389) 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, 9461594 + 9461595.

It is an arithmetic number, because the mean of its divisors is an integer number (9461595).

Almost surely, 2^18923189 is an apocalyptic number.

It is an amenable number.

18923189 is a deficient number, since it is larger than the sum of its proper divisors (1).

18923189 is an equidigital number, since it uses as much as digits as its factorization.

18923189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 41.

The square root of 18923189 is about 4350.0791946814. The cubic root of 18923189 is about 266.4800957130.

The spelling of 18923189 in words is "eighteen million, nine hundred twenty-three thousand, one hundred eighty-nine".