221211111181 has 2 divisors, whose sum is σ = 221211111182. Its totient is φ = 221211111180.

The previous prime is 221211111137. The next prime is 221211111227. The reversal of 221211111181 is 181111112122.

221211111181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 194886048681 + 26325062500 = 441459^2 + 162250^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221211111181 is a prime.

It is a super-2 number, since 2×221211111181² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221211118181) 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, 110605555590 + 110605555591.

It is an arithmetic number, because the mean of its divisors is an integer number (110605555591).

Almost surely, 2^221211111181 is an apocalyptic number.

It is an amenable number.

221211111181 is a deficient number, since it is larger than the sum of its proper divisors (1).

221211111181 is an equidigital number, since it uses as much as digits as its factorization.

221211111181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64, while the sum is 22.

The spelling of 221211111181 in words is "two hundred twenty-one billion, two hundred eleven million, one hundred eleven thousand, one hundred eighty-one".