18091039 has 4 divisors (see below), whose sum is σ = 18580024. Its totient is φ = 17602056.

The previous prime is 18091037. The next prime is 18091049. The reversal of 18091039 is 93019081.

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 18091039 - 2¹ = 18091037 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18091039.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18091033) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 244437 + ... + 244510.

It is an arithmetic number, because the mean of its divisors is an integer number (4645006).

Almost surely, 2^18091039 is an apocalyptic number.

18091039 is a deficient number, since it is larger than the sum of its proper divisors (488985).

18091039 is an equidigital number, since it uses as much as digits as its factorization.

18091039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488984.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 18091039 is about 4253.3562042227. The cubic root of 18091039 is about 262.5152293507.

It can be divided in two parts, 180 and 91039, that added together give a palindrome (91219).

The spelling of 18091039 in words is "eighteen million, ninety-one thousand, thirty-nine".