111555165161 has 16 divisors (see below), whose sum is σ = 124215674688. Its totient is φ = 99321393600.

The previous prime is 111555165119. The next prime is 111555165203. The reversal of 111555165161 is 161561555111.

It is an interprime number because it is at equal distance from previous prime (111555165119) and next prime (111555165203).

It is a de Polignac number, because none of the positive numbers 2^k-111555165161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111555165361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 152966 + ... + 496496.

It is an arithmetic number, because the mean of its divisors is an integer number (7763479668).

Almost surely, 2^111555165161 is an apocalyptic number.

111555165161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111555165161 is a deficient number, since it is larger than the sum of its proper divisors (12660509527).

111555165161 is a wasteful number, since it uses less digits than its factorization.

111555165161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 344152.

The product of its digits is 22500, while the sum is 38.

The spelling of 111555165161 in words is "one hundred eleven billion, five hundred fifty-five million, one hundred sixty-five thousand, one hundred sixty-one".