220511221 has 6 divisors (see below), whose sum is σ = 256513110. Its totient is φ = 189009576.

The previous prime is 220511197. The next prime is 220511297. The reversal of 220511221 is 122115022.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 164096100 + 56415121 = 12810^2 + 7511^2 .

It is not a de Polignac number, because 220511221 - 2¹⁹ = 219986933 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 220511195 and 220511204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220511021) 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 5 ways as a sum of consecutive naturals, for example, 2250066 + ... + 2250163.

It is an arithmetic number, because the mean of its divisors is an integer number (42752185).

Almost surely, 2^220511221 is an apocalyptic number.

It is an amenable number.

220511221 is a deficient number, since it is larger than the sum of its proper divisors (36001889).

220511221 is an equidigital number, since it uses as much as digits as its factorization.

220511221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4500243 (or 4500236 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 220511221 is about 14849.6202308342. The cubic root of 220511221 is about 604.1483095958.

Adding to 220511221 its reverse (122115022), we get a palindrome (342626243).

The spelling of 220511221 in words is "two hundred twenty million, five hundred eleven thousand, two hundred twenty-one".