111999221 has 2 divisors, whose sum is σ = 111999222. Its totient is φ = 111999220.

The previous prime is 111999211. The next prime is 111999227. The reversal of 111999221 is 122999111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81252196 + 30747025 = 9014^2 + 5545^2 .

It is a cyclic number.

It is not a de Polignac number, because 111999221 - 2¹⁰ = 111998197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111999227) 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 as a sum of consecutive naturals, namely, 55999610 + 55999611.

It is an arithmetic number, because the mean of its divisors is an integer number (55999611).

Almost surely, 2^111999221 is an apocalyptic number.

It is an amenable number.

111999221 is a deficient number, since it is larger than the sum of its proper divisors (1).

111999221 is an equidigital number, since it uses as much as digits as its factorization.

111999221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2916, while the sum is 35.

The square root of 111999221 is about 10582.9684399038. The cubic root of 111999221 is about 482.0273352724.

The spelling of 111999221 in words is "one hundred eleven million, nine hundred ninety-nine thousand, two hundred twenty-one".