18221305 has 8 divisors (see below), whose sum is σ = 21988800. Its totient is φ = 14494896.

The previous prime is 18221257. The next prime is 18221339. The reversal of 18221305 is 50312281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18221305 - 2¹³ = 18213113 is a prime.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 9285 + ... + 11074.

It is an arithmetic number, because the mean of its divisors is an integer number (2748600).

Almost surely, 2^18221305 is an apocalyptic number.

It is an amenable number.

18221305 is a deficient number, since it is larger than the sum of its proper divisors (3767495).

18221305 is a wasteful number, since it uses less digits than its factorization.

18221305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20543.

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

The square root of 18221305 is about 4268.6420557362. The cubic root of 18221305 is about 263.1438104708.

Adding to 18221305 its reverse (50312281), we get a palindrome (68533586).

The spelling of 18221305 in words is "eighteen million, two hundred twenty-one thousand, three hundred five".