18221214 has 16 divisors (see below), whose sum is σ = 39755520. Its totient is φ = 5521560.

The previous prime is 18221213. The next prime is 18221233. The reversal of 18221214 is 41212281.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18221213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 137974 + ... + 138105.

It is an arithmetic number, because the mean of its divisors is an integer number (2484720).

Almost surely, 2^18221214 is an apocalyptic number.

18221214 is an abundant number, since it is smaller than the sum of its proper divisors (21534306).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18221214 is a wasteful number, since it uses less digits than its factorization.

18221214 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276095.

The product of its digits is 256, while the sum is 21.

The square root of 18221214 is about 4268.6313965954. The cubic root of 18221214 is about 263.1433724098.

Adding to 18221214 its reverse (41212281), we get a palindrome (59433495).

The spelling of 18221214 in words is "eighteen million, two hundred twenty-one thousand, two hundred fourteen".