221966111 has 2 divisors, whose sum is σ = 221966112. Its totient is φ = 221966110.

The previous prime is 221966081. The next prime is 221966117. The reversal of 221966111 is 111669122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221966111 - 2¹⁸ = 221703967 is a prime.

It is equal to p_12224792 and since 221966111 and 12224792 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221966117) 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, 110983055 + 110983056.

It is an arithmetic number, because the mean of its divisors is an integer number (110983056).

Almost surely, 2^221966111 is an apocalyptic number.

221966111 is a deficient number, since it is larger than the sum of its proper divisors (1).

221966111 is an equidigital number, since it uses as much as digits as its factorization.

221966111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 29.

The square root of 221966111 is about 14898.5271419694. The cubic root of 221966111 is about 605.4740823394.

The spelling of 221966111 in words is "two hundred twenty-one million, nine hundred sixty-six thousand, one hundred eleven".