18053221 has 4 divisors (see below), whose sum is σ = 18092844. Its totient is φ = 18013600.

The previous prime is 18053213. The next prime is 18053227. The reversal of 18053221 is 12235081.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6964321 + 11088900 = 2639^2 + 3330^2 .

It is a cyclic number.

It is not a de Polignac number, because 18053221 - 2³ = 18053213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18053192 and 18053201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18053227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19120 + ... + 20041.

It is an arithmetic number, because the mean of its divisors is an integer number (4523211).

Almost surely, 2^18053221 is an apocalyptic number.

It is an amenable number.

18053221 is a deficient number, since it is larger than the sum of its proper divisors (39623).

18053221 is an equidigital number, since it uses as much as digits as its factorization.

18053221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39622.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 18053221 is about 4248.9082127059. The cubic root of 18053221 is about 262.3321787482.

The spelling of 18053221 in words is "eighteen million, fifty-three thousand, two hundred twenty-one".