161605661656863 has 16 divisors (see below), whose sum is σ = 217215092164352. Its totient is φ = 106868734560000.

The previous prime is 161605661656853. The next prime is 161605661656927. The reversal of 161605661656863 is 368656166506161.

It is not a de Polignac number, because 161605661656863 - 2²² = 161605657462559 is a prime.

It is a super-2 number, since 2×161605661656863² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 161605661656794 and 161605661656803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161605661656853) 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 15 ways as a sum of consecutive naturals, for example, 257824018 + ... + 258450063.

It is an arithmetic number, because the mean of its divisors is an integer number (13575943260272).

Almost surely, 2^{161605661656863} is an apocalyptic number.

161605661656863 is a deficient number, since it is larger than the sum of its proper divisors (55609430507489).

161605661656863 is a wasteful number, since it uses less digits than its factorization.

161605661656863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516274926.

The product of its (nonzero) digits is 167961600, while the sum is 66.

The spelling of 161605661656863 in words is "one hundred sixty-one trillion, six hundred five billion, six hundred sixty-one million, six hundred fifty-six thousand, eight hundred sixty-three".