30221 has 4 divisors (see below), whose sum is σ = 30912. Its totient is φ = 29532.

The previous prime is 30211. The next prime is 30223. The reversal of 30221 is 12203.

30221 is nontrivially palindromic in base 5.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 30199 and 30208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (30223) 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, 275 + ... + 368.

It is an arithmetic number, because the mean of its divisors is an integer number (7728).

2³⁰²²¹ is an apocalyptic number.

It is an amenable number.

30221 is a deficient number, since it is larger than the sum of its proper divisors (691).

30221 is an equidigital number, since it uses as much as digits as its factorization.

30221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 690.

The product of its (nonzero) digits is 12, while the sum is 8.

The square root of 30221 is about 173.8418821803. The cubic root of 30221 is about 31.1484382846.

Adding to 30221 its reverse (12203), we get a palindrome (42424).

It can be divided in two parts, 302 and 21, that added together give a palindrome (323).

The spelling of 30221 in words is "thirty thousand, two hundred twenty-one".