18091243 has 2 divisors, whose sum is σ = 18091244. Its totient is φ = 18091242.

The previous prime is 18091217. The next prime is 18091279. The reversal of 18091243 is 34219081.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18091243 is a prime.

It is not a weakly prime, because it can be changed into another prime (18091643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9045621 + 9045622.

It is an arithmetic number, because the mean of its divisors is an integer number (9045622).

Almost surely, 2^18091243 is an apocalyptic number.

18091243 is a deficient number, since it is larger than the sum of its proper divisors (1).

18091243 is an equidigital number, since it uses as much as digits as its factorization.

18091243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 18091243 is about 4253.3801852174. The cubic root of 18091243 is about 262.5162160806.

The spelling of 18091243 in words is "eighteen million, ninety-one thousand, two hundred forty-three".