221220211 has 16 divisors (see below), whose sum is σ = 239247360. Its totient is φ = 203886720.

The previous prime is 221220163. The next prime is 221220229. The reversal of 221220211 is 112022122.

It is a happy number.

It is not a de Polignac number, because 221220211 - 2⁹ = 221219699 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221220191 and 221220200.

It is not an unprimeable number, because it can be changed into a prime (221220611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 169915 + ... + 171211.

It is an arithmetic number, because the mean of its divisors is an integer number (14952960).

Almost surely, 2^221220211 is an apocalyptic number.

221220211 is a deficient number, since it is larger than the sum of its proper divisors (18027149).

221220211 is a wasteful number, since it uses less digits than its factorization.

221220211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1554.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 221220211 is about 14873.4734006553. The cubic root of 221220211 is about 604.7951048984.

Adding to 221220211 its reverse (112022122), we get a palindrome (333242333).

The spelling of 221220211 in words is "two hundred twenty-one million, two hundred twenty thousand, two hundred eleven".