161001655565 has 8 divisors (see below), whose sum is σ = 193861380888. Its totient is φ = 128361728320.

The previous prime is 161001655561. The next prime is 161001655567. The reversal of 161001655565 is 565556100161.

161001655565 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 45436332964 + 115565322601 = 213158^2 + 339949^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 161001655565 - 2² = 161001655561 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 (161001655561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 54947906 + ... + 54950835.

It is an arithmetic number, because the mean of its divisors is an integer number (24232672611).

Almost surely, 2^161001655565 is an apocalyptic number.

It is an amenable number.

161001655565 is a deficient number, since it is larger than the sum of its proper divisors (32859725323).

161001655565 is a wasteful number, since it uses less digits than its factorization.

161001655565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109899039.

The product of its (nonzero) digits is 135000, while the sum is 41.

The spelling of 161001655565 in words is "one hundred sixty-one billion, one million, six hundred fifty-five thousand, five hundred sixty-five".