10221 has 4 divisors (see below), whose sum is σ = 13632. Its totient is φ = 6812.

The previous prime is 10211. The next prime is 10223. The reversal of 10221 is 12201.

It is a happy number.

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 not a de Polignac number, because 10221 - 2⁷ = 10093 is a prime.

It is a D-number.

It is a Curzon number.

10221 is a lucky number.

It is a nialpdrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10223) 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, 1701 + ... + 1706.

It is an arithmetic number, because the mean of its divisors is an integer number (3408).

2¹⁰²²¹ is an apocalyptic number.

It is an amenable number.

10221 is a deficient number, since it is larger than the sum of its proper divisors (3411).

10221 is an equidigital number, since it uses as much as digits as its factorization.

10221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3410.

The product of its (nonzero) digits is 4, while the sum is 6.

The square root of 10221 is about 101.0989614190. The cubic root of 10221 is about 21.7019019053.

Adding to 10221 its reverse (12201), we get a palindrome (22422).

It can be divided in two parts, 10 and 221, that added together give a triangular number (231 = T₂₁).

The spelling of 10221 in words is "ten thousand, two hundred twenty-one", and thus it is an iban number.