18168831321 has 4 divisors (see below), whose sum is σ = 24225108432. Its totient is φ = 12112554212.

The previous prime is 18168831293. The next prime is 18168831337. The reversal of 18168831321 is 12313886181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12313886181 = 3 ⋅4104628727.

It is a cyclic number.

It is not a de Polignac number, because 18168831321 - 2⁷ = 18168831193 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18168831391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3028138551 + ... + 3028138556.

It is an arithmetic number, because the mean of its divisors is an integer number (6056277108).

Almost surely, 2^18168831321 is an apocalyptic number.

It is an amenable number.

18168831321 is a deficient number, since it is larger than the sum of its proper divisors (6056277111).

18168831321 is an equidigital number, since it uses as much as digits as its factorization.

18168831321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6056277110.

The product of its digits is 55296, while the sum is 42.

The spelling of 18168831321 in words is "eighteen billion, one hundred sixty-eight million, eight hundred thirty-one thousand, three hundred twenty-one".