165605655565 has 16 divisors (see below), whose sum is σ = 239069819520. Its totient is φ = 107581417920.

The previous prime is 165605655541. The next prime is 165605655581. The reversal of 165605655565 is 565556506561.

165605655565 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 165605655565 - 2¹¹ = 165605653517 is a prime.

It is a super-2 number, since 2×165605655565² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 124514866 + ... + 124516195.

It is an arithmetic number, because the mean of its divisors is an integer number (14941863720).

Almost surely, 2^165605655565 is an apocalyptic number.

It is an amenable number.

165605655565 is a deficient number, since it is larger than the sum of its proper divisors (73464163955).

165605655565 is a wasteful number, since it uses less digits than its factorization.

165605655565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249031092.

The product of its (nonzero) digits is 20250000, while the sum is 55.

The spelling of 165605655565 in words is "one hundred sixty-five billion, six hundred five million, six hundred fifty-five thousand, five hundred sixty-five".