18221121 has 24 divisors (see below), whose sum is σ = 27181440. Its totient is φ = 11755296.

The previous prime is 18221081. The next prime is 18221123. The reversal of 18221121 is 12112281.

It is not a de Polignac number, because 18221121 - 2¹⁴ = 18204737 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18221094 and 18221103.

It is not an unprimeable number, because it can be changed into a prime (18221123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76120 + ... + 76358.

It is an arithmetic number, because the mean of its divisors is an integer number (1132560).

Almost surely, 2^18221121 is an apocalyptic number.

It is an amenable number.

18221121 is a deficient number, since it is larger than the sum of its proper divisors (8960319).

18221121 is a wasteful number, since it uses less digits than its factorization.

18221121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 485 (or 482 counting only the distinct ones).

The product of its digits is 64, while the sum is 18.

The square root of 18221121 is about 4268.6205031602. The cubic root of 18221121 is about 263.1429247197.

The spelling of 18221121 in words is "eighteen million, two hundred twenty-one thousand, one hundred twenty-one".