161661116061665 has 32 divisors (see below), whose sum is σ = 211687333621632. Its totient is φ = 117539372160000.

The previous prime is 161661116061581. The next prime is 161661116061719. The reversal of 161661116061665 is 566160611166161.

161661116061665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 161661116061665 - 2¹² = 161661116057569 is a prime.

It is a super-2 number, since 2×161661116061665² (a number of 29 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3704997689 + ... + 3705041321.

It is an arithmetic number, because the mean of its divisors is an integer number (6615229175676).

Almost surely, 2^{161661116061665} is an apocalyptic number.

It is an amenable number.

161661116061665 is a deficient number, since it is larger than the sum of its proper divisors (50026217559967).

161661116061665 is a wasteful number, since it uses less digits than its factorization.

161661116061665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60641.

The product of its (nonzero) digits is 1399680, while the sum is 53.

The spelling of 161661116061665 in words is "one hundred sixty-one trillion, six hundred sixty-one billion, one hundred sixteen million, sixty-one thousand, six hundred sixty-five".