18221368 has 16 divisors (see below), whose sum is σ = 37271160. Its totient is φ = 8282400.

The previous prime is 18221341. The next prime is 18221389. The reversal of 18221368 is 86312281.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103443 + ... + 103618.

Almost surely, 2^18221368 is an apocalyptic number.

It is an amenable number.

18221368 is an abundant number, since it is smaller than the sum of its proper divisors (19049792).

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

18221368 is a wasteful number, since it uses less digits than its factorization.

18221368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207078 (or 207074 counting only the distinct ones).

The product of its digits is 4608, while the sum is 31.

The square root of 18221368 is about 4268.6494351258. The cubic root of 18221368 is about 263.1441137429.

It can be divided in two parts, 182213 and 68, that added together give a palindrome (182281).

The spelling of 18221368 in words is "eighteen million, two hundred twenty-one thousand, three hundred sixty-eight".