161265117181 has 16 divisors (see below), whose sum is σ = 188819180928. Its totient is φ = 134840851200.

The previous prime is 161265117179. The next prime is 161265117187. The reversal of 161265117181 is 181711562161.

It is a cyclic number.

It is not a de Polignac number, because 161265117181 - 2¹ = 161265117179 is a prime.

It is a super-2 number, since 2×161265117181² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161265117187) 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, 3099921 + ... + 3151513.

It is an arithmetic number, because the mean of its divisors is an integer number (11801198808).

Almost surely, 2^161265117181 is an apocalyptic number.

It is an amenable number.

161265117181 is a deficient number, since it is larger than the sum of its proper divisors (27554063747).

161265117181 is a wasteful number, since it uses less digits than its factorization.

161265117181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62532.

The product of its digits is 20160, while the sum is 40.

The spelling of 161265117181 in words is "one hundred sixty-one billion, two hundred sixty-five million, one hundred seventeen thousand, one hundred eighty-one".