18123311 has 4 divisors (see below), whose sum is σ = 18352800. Its totient is φ = 17893824.

The previous prime is 18123263. The next prime is 18123323. The reversal of 18123311 is 11332181.

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 18123311 - 2¹⁸ = 17861167 is a prime.

It is a super-3 number, since 3×18123311³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18123331) 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 3 ways as a sum of consecutive naturals, for example, 114626 + ... + 114783.

It is an arithmetic number, because the mean of its divisors is an integer number (4588200).

Almost surely, 2^18123311 is an apocalyptic number.

18123311 is a deficient number, since it is larger than the sum of its proper divisors (229489).

18123311 is an equidigital number, since it uses as much as digits as its factorization.

18123311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229488.

The product of its digits is 144, while the sum is 20.

The square root of 18123311 is about 4257.1482238701. The cubic root of 18123311 is about 262.6712340057.

Adding to 18123311 its reverse (11332181), we get a palindrome (29455492).

The spelling of 18123311 in words is "eighteen million, one hundred twenty-three thousand, three hundred eleven".