111121221161 has 2 divisors, whose sum is σ = 111121221162. Its totient is φ = 111121221160.

The previous prime is 111121221007. The next prime is 111121221179. The reversal of 111121221161 is 161122121111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 110955610000 + 165611161 = 333100^2 + 12869^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111121221161 is a prime.

It is not a weakly prime, because it can be changed into another prime (111121121161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55560610580 + 55560610581.

It is an arithmetic number, because the mean of its divisors is an integer number (55560610581).

Almost surely, 2^111121221161 is an apocalyptic number.

It is an amenable number.

111121221161 is a deficient number, since it is larger than the sum of its proper divisors (1).

111121221161 is an equidigital number, since it uses as much as digits as its factorization.

111121221161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48, while the sum is 20.

Adding to 111121221161 its reverse (161122121111), we get a palindrome (272243342272).

The spelling of 111121221161 in words is "one hundred eleven billion, one hundred twenty-one million, two hundred twenty-one thousand, one hundred sixty-one".