220211221 has 4 divisors (see below), whose sum is σ = 221068332. Its totient is φ = 219354112.

The previous prime is 220211203. The next prime is 220211227. The reversal of 220211221 is 122112022.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 98903025 + 121308196 = 9945^2 + 11014^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-220211221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220211227) 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, 428170 + ... + 428683.

It is an arithmetic number, because the mean of its divisors is an integer number (55267083).

Almost surely, 2^220211221 is an apocalyptic number.

It is an amenable number.

220211221 is a deficient number, since it is larger than the sum of its proper divisors (857111).

220211221 is an equidigital number, since it uses as much as digits as its factorization.

220211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 857110.

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

The square root of 220211221 is about 14839.5155244368. The cubic root of 220211221 is about 603.8742090351.

Adding to 220211221 its reverse (122112022), we get a palindrome (342323243).

The spelling of 220211221 in words is "two hundred twenty million, two hundred eleven thousand, two hundred twenty-one".