18081443 has 4 divisors (see below), whose sum is σ = 18329208. Its totient is φ = 17833680.

The previous prime is 18081439. The next prime is 18081461. The reversal of 18081443 is 34418081.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18081443 - 2² = 18081439 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18081643) 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, 123773 + ... + 123918.

It is an arithmetic number, because the mean of its divisors is an integer number (4582302).

Almost surely, 2^18081443 is an apocalyptic number.

18081443 is a deficient number, since it is larger than the sum of its proper divisors (247765).

18081443 is an equidigital number, since it uses as much as digits as its factorization.

18081443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247764.

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 18081443 is about 4252.2280042350. The cubic root of 18081443 is about 262.4688059682.

The spelling of 18081443 in words is "eighteen million, eighty-one thousand, four hundred forty-three".