18001091 has 8 divisors (see below), whose sum is σ = 18718224. Its totient is φ = 17297280.

The previous prime is 18001073. The next prime is 18001099. The reversal of 18001091 is 19010081.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18001091 - 2¹⁰ = 18000067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18001099) 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 in 7 ways as a sum of consecutive naturals, for example, 530 + ... + 6023.

It is an arithmetic number, because the mean of its divisors is an integer number (2339778).

Almost surely, 2^18001091 is an apocalyptic number.

18001091 is a deficient number, since it is larger than the sum of its proper divisors (717133).

18001091 is an equidigital number, since it uses as much as digits as its factorization.

18001091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6661.

The product of its (nonzero) digits is 72, while the sum is 20.

The square root of 18001091 is about 4242.7692607541. The cubic root of 18001091 is about 262.0794341822.

The spelling of 18001091 in words is "eighteen million, one thousand, ninety-one".