18226221 has 24 divisors (see below), whose sum is σ = 26916960. Its totient is φ = 10902144.

The previous prime is 18226207. The next prime is 18226249. The reversal of 18226221 is 12262281.

It is not a de Polignac number, because 18226221 - 2⁷ = 18226093 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18226191 and 18226200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18226121) 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 23 ways as a sum of consecutive naturals, for example, 204745 + ... + 204833.

It is an arithmetic number, because the mean of its divisors is an integer number (1121540).

Almost surely, 2^18226221 is an apocalyptic number.

It is an amenable number.

18226221 is a deficient number, since it is larger than the sum of its proper divisors (8690739).

18226221 is an equidigital number, since it uses as much as digits as its factorization.

18226221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253 (or 164 counting only the distinct ones).

The product of its digits is 768, while the sum is 24.

The square root of 18226221 is about 4269.2178440553. The cubic root of 18226221 is about 263.1674732226.

The spelling of 18226221 in words is "eighteen million, two hundred twenty-six thousand, two hundred twenty-one".