161660101165 has 4 divisors (see below), whose sum is σ = 193992121404. Its totient is φ = 129328080928.

The previous prime is 161660101133. The next prime is 161660101199. The reversal of 161660101165 is 561101066161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 561101066161 = 4463 ⋅125722847.

It can be written as a sum of positive squares in 2 ways, for example, as 42457014601 + 119203086564 = 206051^2 + 345258^2 .

It is a cyclic number.

It is not a de Polignac number, because 161660101165 - 2⁵ = 161660101133 is a prime.

It is a super-2 number, since 2×161660101165² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161660101165.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16166010112 + ... + 16166010121.

It is an arithmetic number, because the mean of its divisors is an integer number (48498030351).

Almost surely, 2^161660101165 is an apocalyptic number.

It is an amenable number.

161660101165 is a deficient number, since it is larger than the sum of its proper divisors (32332020239).

161660101165 is an equidigital number, since it uses as much as digits as its factorization.

161660101165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32332020238.

The product of its (nonzero) digits is 6480, while the sum is 34.

The spelling of 161660101165 in words is "one hundred sixty-one billion, six hundred sixty million, one hundred one thousand, one hundred sixty-five".