161181265727 has 4 divisors (see below), whose sum is σ = 161191220976. Its totient is φ = 161171310480.

The previous prime is 161181265717. The next prime is 161181265733. The reversal of 161181265727 is 727562181161.

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

It is a cyclic number.

It is not a de Polignac number, because 161181265727 - 2³⁰ = 160107523903 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161181265717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4953299 + ... + 4985732.

It is an arithmetic number, because the mean of its divisors is an integer number (40297805244).

Almost surely, 2^161181265727 is an apocalyptic number.

161181265727 is a deficient number, since it is larger than the sum of its proper divisors (9955249).

161181265727 is an equidigital number, since it uses as much as digits as its factorization.

161181265727 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9955248.

The product of its digits is 282240, while the sum is 47.

The spelling of 161181265727 in words is "one hundred sixty-one billion, one hundred eighty-one million, two hundred sixty-five thousand, seven hundred twenty-seven".