111131021161 has 2 divisors, whose sum is σ = 111131021162. Its totient is φ = 111131021160.

The previous prime is 111131021101. The next prime is 111131021171. The reversal of 111131021161 is 161120131111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 104115283561 + 7015737600 = 322669^2 + 83760^2 .

It is an emirp because it is prime and its reverse (161120131111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 111131021161 - 2¹¹ = 111131019113 is a prime.

It is not a weakly prime, because it can be changed into another prime (111131021101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55565510580 + 55565510581.

It is an arithmetic number, because the mean of its divisors is an integer number (55565510581).

Almost surely, 2^111131021161 is an apocalyptic number.

It is an amenable number.

111131021161 is a deficient number, since it is larger than the sum of its proper divisors (1).

111131021161 is an equidigital number, since it uses as much as digits as its factorization.

111131021161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 19.

Adding to 111131021161 its reverse (161120131111), we get a palindrome (272251152272).

The spelling of 111131021161 in words is "one hundred eleven billion, one hundred thirty-one million, twenty-one thousand, one hundred sixty-one".