111111111122161 has 2 divisors, whose sum is σ = 111111111122162. Its totient is φ = 111111111122160.

The previous prime is 111111111122093. The next prime is 111111111122191. The reversal of 111111111122161 is 161221111111111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66501268638561 + 44609842483600 = 8154831^2 + 6679060^2 .

It is a cyclic number.

It is not a de Polignac number, because 111111111122161 - 2¹³ = 111111111113969 is a prime.

It is not a weakly prime, because it can be changed into another prime (111111111122191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55555555561080 + 55555555561081.

It is an arithmetic number, because the mean of its divisors is an integer number (55555555561081).

Almost surely, 2^{111111111122161} is an apocalyptic number.

It is an amenable number.

111111111122161 is a deficient number, since it is larger than the sum of its proper divisors (1).

111111111122161 is an equidigital number, since it uses as much as digits as its factorization.

111111111122161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24, while the sum is 22.

Adding to 111111111122161 its reverse (161221111111111), we get a palindrome (272332222233272).

The spelling of 111111111122161 in words is "one hundred eleven trillion, one hundred eleven billion, one hundred eleven million, one hundred twenty-two thousand, one hundred sixty-one".