1111220221 has 2 divisors, whose sum is σ = 1111220222. Its totient is φ = 1111220220.

The previous prime is 1111220213. The next prime is 1111220251. The reversal of 1111220221 is 1220221111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 880605625 + 230614596 = 29675^2 + 15186^2 .

It is an emirp because it is prime and its reverse (1220221111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1111220221 - 2³ = 1111220213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1111220251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 555610110 + 555610111.

It is an arithmetic number, because the mean of its divisors is an integer number (555610111).

Almost surely, 2^1111220221 is an apocalyptic number.

It is an amenable number.

1111220221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1111220221 is an equidigital number, since it uses as much as digits as its factorization.

1111220221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 1111220221 is about 33334.9699414894. The cubic root of 1111220221 is about 1035.7780705209.

Adding to 1111220221 its reverse (1220221111), we get a palindrome (2331441332).

It can be divided in two parts, 111 and 1220221, that multiplied together give a palindrome (135444531).

The spelling of 1111220221 in words is "one billion, one hundred eleven million, two hundred twenty thousand, two hundred twenty-one".