18243389 has 2 divisors, whose sum is σ = 18243390. Its totient is φ = 18243388.

The previous prime is 18243377. The next prime is 18243403. The reversal of 18243389 is 98334281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18207289 + 36100 = 4267^2 + 190^2 .

It is a cyclic number.

It is not a de Polignac number, because 18243389 - 2⁸ = 18243133 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 (18243689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9121694 + 9121695.

It is an arithmetic number, because the mean of its divisors is an integer number (9121695).

Almost surely, 2^18243389 is an apocalyptic number.

It is an amenable number.

18243389 is a deficient number, since it is larger than the sum of its proper divisors (1).

18243389 is an equidigital number, since it uses as much as digits as its factorization.

18243389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 38.

The square root of 18243389 is about 4271.2280435491. The cubic root of 18243389 is about 263.2500765837.

The spelling of 18243389 in words is "eighteen million, two hundred forty-three thousand, three hundred eighty-nine".