165600661655 has 16 divisors (see below), whose sum is σ = 233462192544. Its totient is φ = 111172471680.

The previous prime is 165600661627. The next prime is 165600661657. The reversal of 165600661655 is 556166006561.

It is not a de Polignac number, because 165600661655 - 2⁸ = 165600661399 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 (165600661657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 115803944 + ... + 115805373.

It is an arithmetic number, because the mean of its divisors is an integer number (14591387034).

Almost surely, 2^165600661655 is an apocalyptic number.

165600661655 is a deficient number, since it is larger than the sum of its proper divisors (67861530889).

165600661655 is a wasteful number, since it uses less digits than its factorization.

165600661655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231609346.

The product of its (nonzero) digits is 972000, while the sum is 47.

The spelling of 165600661655 in words is "one hundred sixty-five billion, six hundred million, six hundred sixty-one thousand, six hundred fifty-five".