161566616115577 has 4 divisors (see below), whose sum is σ = 165933281416036. Its totient is φ = 157199950815120.

The previous prime is 161566616115571. The next prime is 161566616115587. The reversal of 161566616115577 is 775511616665161.

161566616115577 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 99853273860921 + 61713342254656 = 9992661^2 + 7855784^2 .

It is a cyclic number.

It is not a de Polignac number, because 161566616115577 - 2²³ = 161566607726969 is a prime.

It is a super-2 number, since 2×161566616115577² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161566616115571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2183332650174 + ... + 2183332650247.

It is an arithmetic number, because the mean of its divisors is an integer number (41483320354009).

Almost surely, 2^{161566616115577} is an apocalyptic number.

It is an amenable number.

161566616115577 is a deficient number, since it is larger than the sum of its proper divisors (4366665300459).

161566616115577 is an equidigital number, since it uses as much as digits as its factorization.

161566616115577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4366665300458.

The product of its digits is 47628000, while the sum is 64.

The spelling of 161566616115577 in words is "one hundred sixty-one trillion, five hundred sixty-six billion, six hundred sixteen million, one hundred fifteen thousand, five hundred seventy-seven".