111666506161 has 16 divisors (see below), whose sum is σ = 133399526400. Its totient is φ = 93379644960.

The previous prime is 111666506141. The next prime is 111666506177. The reversal of 111666506161 is 161605666111.

It is a de Polignac number, because none of the positive numbers 2^k-111666506161 is a prime.

It is not an unprimeable number, because it can be changed into a prime (111666506111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3956161 + ... + 3984286.

It is an arithmetic number, because the mean of its divisors is an integer number (8337470400).

Almost surely, 2^111666506161 is an apocalyptic number.

It is an amenable number.

111666506161 is a deficient number, since it is larger than the sum of its proper divisors (21733020239).

111666506161 is an frugal number, since it uses more digits than its factorization.

111666506161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7940509 (or 7940495 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 40.

The spelling of 111666506161 in words is "one hundred eleven billion, six hundred sixty-six million, five hundred six thousand, one hundred sixty-one".