201111221 has 2 divisors, whose sum is σ = 201111222. Its totient is φ = 201111220.

The previous prime is 201111217. The next prime is 201111227. The reversal of 201111221 is 122111102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 193488100 + 7623121 = 13910^2 + 2761^2 .

It is a cyclic number.

It is not a de Polignac number, because 201111221 - 2² = 201111217 is a prime.

It is a super-2 number, since 2×201111221² = 80891446424221682, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201111227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100555610 + 100555611.

It is an arithmetic number, because the mean of its divisors is an integer number (100555611).

Almost surely, 2^201111221 is an apocalyptic number.

It is an amenable number.

201111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

201111221 is an equidigital number, since it uses as much as digits as its factorization.

201111221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 201111221 is about 14181.3687985328. The cubic root of 201111221 is about 585.8846245539.

Adding to 201111221 its reverse (122111102), we get a palindrome (323222323).

The spelling of 201111221 in words is "two hundred one million, one hundred eleven thousand, two hundred twenty-one".