18840389 has 2 divisors, whose sum is σ = 18840390. Its totient is φ = 18840388.

The previous prime is 18840383. The next prime is 18840397. The reversal of 18840389 is 98304881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12837889 + 6002500 = 3583^2 + 2450^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18840389 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 (18840383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9420194 + 9420195.

It is an arithmetic number, because the mean of its divisors is an integer number (9420195).

Almost surely, 2^18840389 is an apocalyptic number.

It is an amenable number.

18840389 is a deficient number, since it is larger than the sum of its proper divisors (1).

18840389 is an equidigital number, since it uses as much as digits as its factorization.

18840389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 55296, while the sum is 41.

The square root of 18840389 is about 4340.5516930455. The cubic root of 18840389 is about 266.0908587800.

The spelling of 18840389 in words is "eighteen million, eight hundred forty thousand, three hundred eighty-nine".