165821785089 has 16 divisors (see below), whose sum is σ = 226096738560. Its totient is φ = 108053528960.

The previous prime is 165821785057. The next prime is 165821785117. The reversal of 165821785089 is 980587128561.

165821785089 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 165821785089 - 2⁵ = 165821785057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165821785889) 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 15 ways as a sum of consecutive naturals, for example, 665394 + ... + 879995.

It is an arithmetic number, because the mean of its divisors is an integer number (14131046160).

Almost surely, 2^165821785089 is an apocalyptic number.

It is an amenable number.

165821785089 is a deficient number, since it is larger than the sum of its proper divisors (60274953471).

165821785089 is a wasteful number, since it uses less digits than its factorization.

165821785089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1546200.

The product of its (nonzero) digits is 9676800, while the sum is 60.

The spelling of 165821785089 in words is "one hundred sixty-five billion, eight hundred twenty-one million, seven hundred eighty-five thousand, eighty-nine".