18081839 has 4 divisors (see below), whose sum is σ = 18091824. Its totient is φ = 18071856.

The previous prime is 18081821. The next prime is 18081853. The reversal of 18081839 is 93818081.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 18081839 - 2¹⁶ = 18016303 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18081859) 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 in 3 ways as a sum of consecutive naturals, for example, 1427 + ... + 6180.

It is an arithmetic number, because the mean of its divisors is an integer number (4522956).

Almost surely, 2^18081839 is an apocalyptic number.

18081839 is a deficient number, since it is larger than the sum of its proper divisors (9985).

18081839 is an equidigital number, since it uses as much as digits as its factorization.

18081839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9984.

The product of its (nonzero) digits is 13824, while the sum is 38.

The square root of 18081839 is about 4252.2745678049. The cubic root of 18081839 is about 262.4707220558.

The spelling of 18081839 in words is "eighteen million, eighty-one thousand, eight hundred thirty-nine".