18001211 has 4 divisors (see below), whose sum is σ = 18068400. Its totient is φ = 17934024.

The previous prime is 18001201. The next prime is 18001213. The reversal of 18001211 is 11210081.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18001211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18001213) 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, 33191 + ... + 33728.

It is an arithmetic number, because the mean of its divisors is an integer number (4517100).

Almost surely, 2^18001211 is an apocalyptic number.

18001211 is a deficient number, since it is larger than the sum of its proper divisors (67189).

18001211 is an equidigital number, since it uses as much as digits as its factorization.

18001211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67188.

The product of its (nonzero) digits is 16, while the sum is 14.

The square root of 18001211 is about 4242.7834024376. The cubic root of 18001211 is about 262.0800165443.

Adding to 18001211 its reverse (11210081), we get a palindrome (29211292).

The spelling of 18001211 in words is "eighteen million, one thousand, two hundred eleven".