17221 has 4 divisors (see below), whose sum is σ = 18252. Its totient is φ = 16192.

The previous prime is 17209. The next prime is 17231. The reversal of 17221 is 12271.

17221 is an esthetic number in base 16, because in such base its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12271 = 7 ⋅1753.

It can be written as a sum of positive squares in 2 ways, for example, as 4900 + 12321 = 70^2 + 111^2 .

It is a cyclic number.

It is not a de Polignac number, because 17221 - 2⁵ = 17189 is a prime.

It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

17221 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17231) 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, 490 + ... + 523.

It is an arithmetic number, because the mean of its divisors is an integer number (4563).

2¹⁷²²¹ is an apocalyptic number.

It is an amenable number.

17221 is a deficient number, since it is larger than the sum of its proper divisors (1031).

17221 is a wasteful number, since it uses less digits than its factorization.

17221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1030.

The product of its digits is 28, while the sum is 13.

The square root of 17221 is about 131.2288078129. The cubic root of 17221 is about 25.8237587365.

Adding to 17221 its reverse (12271), we get a palindrome (29492).

Subtracting from 17221 its reverse (12271), we obtain a triangular number (4950 = T₉₉).

The spelling of 17221 in words is "seventeen thousand, two hundred twenty-one", and thus it is an iban number.