165989888899 has 4 divisors (see below), whose sum is σ = 166266079000. Its totient is φ = 165713698800.

The previous prime is 165989888821. The next prime is 165989889017. The reversal of 165989888899 is 998888989561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165989888899 - 2³³ = 157399954307 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165989838899) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138094149 + ... + 138095350.

It is an arithmetic number, because the mean of its divisors is an integer number (41566519750).

Almost surely, 2^165989888899 is an apocalyptic number.

165989888899 is a deficient number, since it is larger than the sum of its proper divisors (276190101).

165989888899 is an equidigital number, since it uses as much as digits as its factorization.

165989888899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276190100.

The product of its digits is 6449725440, while the sum is 88.

The spelling of 165989888899 in words is "one hundred sixty-five billion, nine hundred eighty-nine million, eight hundred eighty-eight thousand, eight hundred ninety-nine".