18326389 has 2 divisors, whose sum is σ = 18326390. Its totient is φ = 18326388.

The previous prime is 18326387. The next prime is 18326401. The reversal of 18326389 is 98362381.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16200625 + 2125764 = 4025^2 + 1458^2 .

It is a cyclic number.

It is not a de Polignac number, because 18326389 - 2¹ = 18326387 is a prime.

Together with 18326387, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18326387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9163194 + 9163195.

It is an arithmetic number, because the mean of its divisors is an integer number (9163195).

Almost surely, 2^18326389 is an apocalyptic number.

It is an amenable number.

18326389 is a deficient number, since it is larger than the sum of its proper divisors (1).

18326389 is an equidigital number, since it uses as much as digits as its factorization.

18326389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 62208, while the sum is 40.

The square root of 18326389 is about 4280.9331926579. The cubic root of 18326389 is about 263.6486995957.

The spelling of 18326389 in words is "eighteen million, three hundred twenty-six thousand, three hundred eighty-nine".