11220221 has 4 divisors (see below), whose sum is σ = 11880252. Its totient is φ = 10560192.

The previous prime is 11220211. The next prime is 11220227. The reversal of 11220221 is 12202211.

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 6180196 + 5040025 = 2486^2 + 2245^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11220221 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 (11220227) 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, 329990 + ... + 330023.

It is an arithmetic number, because the mean of its divisors is an integer number (2970063).

Almost surely, 2^11220221 is an apocalyptic number.

It is an amenable number.

11220221 is a deficient number, since it is larger than the sum of its proper divisors (660031).

11220221 is an equidigital number, since it uses as much as digits as its factorization.

11220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 660030.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 11220221 is about 3349.6598334756. The cubic root of 11220221 is about 223.8723563274.

Adding to 11220221 its reverse (12202211), we get a palindrome (23422432).

The spelling of 11220221 in words is "eleven million, two hundred twenty thousand, two hundred twenty-one".