221206 has 4 divisors (see below), whose sum is σ = 331812. Its totient is φ = 110602.

The previous prime is 221203. The next prime is 221209. The reversal of 221206 is 602122.

It is a happy number.

221206 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (221203) and next prime (221209).

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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (221201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55300 + ... + 55303.

It is an arithmetic number, because the mean of its divisors is an integer number (82953).

2²²¹²⁰⁶ is an apocalyptic number.

221206 is a deficient number, since it is larger than the sum of its proper divisors (110606).

221206 is a wasteful number, since it uses less digits than its factorization.

221206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110605.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 221206 is about 470.3254192578. The cubic root of 221206 is about 60.4782154112.

Adding to 221206 its reverse (602122), we get a palindrome (823328).

The spelling of 221206 in words is "two hundred twenty-one thousand, two hundred six".